The politics of global warming

International Nuclear Information System (INIS)

Moss, N.

1991-01-01

The probable warming of the world over the next few decades due to human activity presents a unique threat. The threat of global warming has been brought about by the activities of the entire human race, and only action by a large part of the human race can slow down the process or halt it. Other unwanted effects of industrial activity are trans-national, and require international agreements to regulate them, most obviously radioactivity from nuclear power accidents, acid rain and river pollution; but climatic change, unlike these, is global. International negotiations are going on now to deal with the problem of global warming, mostly by reducing the emission of gases that contribute to it. These are preliminary, yet already different perceptions and conflicting interests are emerging. The aim of the present negotiations is a convention for the UN Conference on Environment and Development (UNCED) to be held in June 1992, the so-called ''Earth Summit''. (author)

A Robust Response of Precipitation to Global Warming from CMIP5 Models

Science.gov (United States)

Lau, K. -M.; Wu, H. -T.; Kim, K. -M.

2012-01-01

How precipitation responds to global warming is a major concern to society and a challenge to climate change research. Based on analyses of rainfall probability distribution functions of 14 state-of-the-art climate models, we find a robust, canonical global rainfall response to a triple CO2 warming scenario, featuring 100 250% more heavy rain, 5-10% less moderate rain, and 10-15% more very light or no-rain events. Regionally, a majority of the models project a consistent response with more heavy rain events over climatologically wet regions of the deep tropics, and more dry events over subtropical and tropical land areas. Results suggest that increased CO2 emissions induce basic structural changes in global rain systems, increasing risks of severe floods and droughts in preferred geographic locations worldwide.

The Impacts of Atmospheric Moisture Transportation on Warm Sector Torrential Rains over South China

Directory of Open Access Journals (Sweden)

Shuixin Zhong

2017-06-01

Full Text Available Warm Sector Torrential Rains (WSTRs occurring during the outbreak of the monsoon in May of 2015 in South China were studied using surface automatic weather observational data, sounding, European Centre for Medium-Range Weather Forecasts Reanalysis interim Data (ERA-interim, satellite and radar data, and a four-level nested grid simulation with the finest grid spacing of 1 km using the Weather Research and Forecasting model (WRF. The results show that the extreme precipitation event, which had maximum rainfall amounts of 406.3 mm in 10 h and 542.2 mm in 24 h on 20 May 2015, and was characterized by its rapid development and its highly concentrated and long duration of heavy rainfall, occurred over the trumpet-shaped topography of Haifeng. The simulation results indicated that the South China Sea (SCS atmospheric moisture transportation (AMT was crucial in triggering the precipitation of the WSTR over South China. The simulation of the WSTR was conducted by using the total energy-mass flux scheme (TEMF, which provided a reasonable simulation of the circulation and the vertical profile in the Planetary Boundary Layer (PBL as well as the estimation of the precipitation. The AMT, which extends from the Beibu Gulf and the South China Sea to the coastal areas and provides Shanwei with a considerable amount of moisture in the boundary layer, and the effects within the PBL, which include orographic effects, an extra low-level jet, and a high-energy tongue characterized by a high-potential pseudo-equivalent temperature tongue with a warm and moist southwesterly wind, were the important large-scale factors causing the WSTR.

Rain: A New Concurrent Process-Oriented Programming Language

OpenAIRE

Brown, Neil C.C.

2006-01-01

This paper details the design of a new concurrent process-oriented programming language, Rain. The language borrows heavily from occam-p and C++ to create a new language based on process-oriented programming, marrying channel-based communication, a clear division between statement and expression, and elements of functional programming. An expressive yet simple type system, coupled with templates, underpins the language. Modern features such as Unicode support and 64-bit integers are included ...

How do changes in warm-phase microphysics affect deep convective clouds?

Science.gov (United States)

Chen, Qian; Koren, Ilan; Altaratz, Orit; Heiblum, Reuven H.; Dagan, Guy; Pinto, Lital

2017-08-01

Understanding aerosol effects on deep convective clouds and the derived effects on the radiation budget and rain patterns can largely contribute to estimations of climate uncertainties. The challenge is difficult in part because key microphysical processes in the mixed and cold phases are still not well understood. For deep convective clouds with a warm base, understanding aerosol effects on the warm processes is extremely important as they set the initial and boundary conditions for the cold processes. Therefore, the focus of this study is the warm phase, which can be better resolved. The main question is: How do aerosol-derived changes in the warm phase affect the properties of deep convective cloud systems? To explore this question, we used a weather research and forecasting (WRF) model with spectral bin microphysics to simulate a deep convective cloud system over the Marshall Islands during the Kwajalein Experiment (KWAJEX). The model results were validated against observations, showing similarities in the vertical profile of radar reflectivity and the surface rain rate. Simulations with larger aerosol loading resulted in a larger total cloud mass, a larger cloud fraction in the upper levels, and a larger frequency of strong updrafts and rain rates. Enlarged mass both below and above the zero temperature level (ZTL) contributed to the increase in cloud total mass (water and ice) in the polluted runs. Increased condensation efficiency of cloud droplets governed the gain in mass below the ZTL, while both enhanced condensational and depositional growth led to increased mass above it. The enhanced mass loading above the ZTL acted to reduce the cloud buoyancy, while the thermal buoyancy (driven by the enhanced latent heat release) increased in the polluted runs. The overall effect showed an increased upward transport (across the ZTL) of liquid water driven by both larger updrafts and larger droplet mobility. These aerosol effects were reflected in the larger ratio

How do changes in warm-phase microphysics affect deep convective clouds?

Directory of Open Access Journals (Sweden)

Q. Chen

2017-08-01

Full Text Available Understanding aerosol effects on deep convective clouds and the derived effects on the radiation budget and rain patterns can largely contribute to estimations of climate uncertainties. The challenge is difficult in part because key microphysical processes in the mixed and cold phases are still not well understood. For deep convective clouds with a warm base, understanding aerosol effects on the warm processes is extremely important as they set the initial and boundary conditions for the cold processes. Therefore, the focus of this study is the warm phase, which can be better resolved. The main question is: How do aerosol-derived changes in the warm phase affect the properties of deep convective cloud systems? To explore this question, we used a weather research and forecasting (WRF model with spectral bin microphysics to simulate a deep convective cloud system over the Marshall Islands during the Kwajalein Experiment (KWAJEX. The model results were validated against observations, showing similarities in the vertical profile of radar reflectivity and the surface rain rate. Simulations with larger aerosol loading resulted in a larger total cloud mass, a larger cloud fraction in the upper levels, and a larger frequency of strong updrafts and rain rates. Enlarged mass both below and above the zero temperature level (ZTL contributed to the increase in cloud total mass (water and ice in the polluted runs. Increased condensation efficiency of cloud droplets governed the gain in mass below the ZTL, while both enhanced condensational and depositional growth led to increased mass above it. The enhanced mass loading above the ZTL acted to reduce the cloud buoyancy, while the thermal buoyancy (driven by the enhanced latent heat release increased in the polluted runs. The overall effect showed an increased upward transport (across the ZTL of liquid water driven by both larger updrafts and larger droplet mobility. These aerosol effects were reflected in the

Rain increases methane production and methane oxidation in a boreal thermokarst bog

Science.gov (United States)

Neumann, R. B.; Moorberg, C.; Turner, J.; Wong, A.; Waldrop, M. P.; Euskirchen, E. S.; Edgar, C.; Turetsky, M. R.

2017-12-01

Bottom-up biogeochemical models of wetland methane emissions simulate the response of methane production, oxidation and transport to wetland conditions and environmental forcings. One reason for mismatches between bottom-up and top-down estimates of emissions is incomplete knowledge of factors and processes that control microbial rates and methane transport. To advance mechanistic understanding of wetland methane emissions, we conducted a multi-year field investigation and plant manipulation experiment in a thermokarst bog located near Fairbanks, Alaska. The edge of the bog is experiencing active permafrost thaw, while the center of the bog thawed 50 to 100 years ago. Our study, which captured both an average year and two of the wettest years on record, revealed how rain interacts with vascular vegetation and recently thawed permafrost to affect methane emissions. In the floating bog, rain water warmed and oxygenated the subsurface, but did not alter soil saturation. The warmer peat temperatures increased both microbial methane production and plant productivity at the edge of the bog near the actively thawing margin, but minimally altered microbial and plant activity in the center of the bog. These responses indicate processes at the edge of the bog were temperature limited while those in the center were not. The compounding effect of increased microbial activity and plant productivity at the edge of the bog doubled methane emissions from treatments with vascular vegetation during rainy years. In contrast, methane emissions from vegetated treatments in the center of the bog did not change with rain. The oxygenating influence of rain facilitated greater methane oxidation in treatments without vascular vegetation, which offset warming-induced increases in methane production at the edge of the bog and decreased methane emissions in the center of the bog. These results elucidate the complex and spatially variable response of methane production and oxidation in

Rain Gauges Handbook

Energy Technology Data Exchange (ETDEWEB)

Bartholomew, M. J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2016-01-01

To improve the quantitative description of precipitation processes in climate models, the Atmospheric Radiation Measurement (ARM) Climate Research Facility deployed rain gauges located near disdrometers (DISD and VDIS data streams). This handbook deals specifically with the rain gauges that make the observations for the RAIN data stream. Other precipitation observations are made by the surface meteorology instrument suite (i.e., MET data stream).

Rain-rate data base development and rain-rate climate analysis

Science.gov (United States)

Crane, Robert K.

1993-01-01

The single-year rain-rate distribution data available within the archives of Consultative Committee for International Radio (CCIR) Study Group 5 were compiled into a data base for use in rain-rate climate modeling and for the preparation of predictions of attenuation statistics. The four year set of tip-time sequences provided by J. Goldhirsh for locations near Wallops Island were processed to compile monthly and annual distributions of rain rate and of event durations for intervals above and below preset thresholds. A four-year data set of tropical rain-rate tip-time sequences were acquired from the NASA TRMM program for 30 gauges near Darwin, Australia. They were also processed for inclusion in the CCIR data base and the expanded data base for monthly observations at the University of Oklahoma. The empirical rain-rate distributions (edfs) accepted for inclusion in the CCIR data base were used to estimate parameters for several rain-rate distribution models: the lognormal model, the Crane two-component model, and the three parameter model proposed by Moupfuma. The intent of this segment of the study is to obtain a limited set of parameters that can be mapped globally for use in rain attenuation predictions. If the form of the distribution can be established, then perhaps available climatological data can be used to estimate the parameters rather than requiring years of rain-rate observations to set the parameters. The two-component model provided the best fit to the Wallops Island data but the Moupfuma model provided the best fit to the Darwin data.

Effect of acid rain on soil microbial processes

International Nuclear Information System (INIS)

Myrold, D.D.; Nason, G.E.

1992-01-01

Acid rain is real; the pH of precipitation in many areas of the world is below its normal equilibrium value, and concentrations of inorganic N and S are elevated above background. The impact of acid rain on soil microbial processes is less clear. This is largely because of the chemical buffering of the soil ecosystem and the inherent resiliency and redundancy of soil microorganisms. Microorganisms have an amazing capacity to adapt to new situations, which is enhanced by their ability to evolve under selection pressure. Their resilience is a function of both the large number of microorganisms present in a given volume of soil and their high growth rate relative to macroorganisms. This suggests that microorganisms are likely to be able to adapt more quickly to acidification than plants or animals, which may be one reason why symbiotic associations, such as ectomycorrhizae, are more susceptible to acid inputs than their saprophytic counterparts

From acid rain to toxic snow

International Nuclear Information System (INIS)

Schindler, D.

1999-01-01

Emerging acid rain problems and problems related to various airborne toxins and effects in soils are discussed by David Schindler, the Volvo Environment Prize winner, a member of the Dept. of Biological Sciences, Univ. of Alberta, Canada. A chain of events involving depletion of basic cations in soils and global warming can result ultimately in a significant threat to indigenous peoples living at high latitudes

The global warming problem

International Nuclear Information System (INIS)

Anon.

1990-01-01

In this chapter, a discussion is presented of the global warming problem and activities contributing to the formation of acid rain, urban smog and to the depletion of the ozone layer. Globally, about two-thirds of anthropogenic carbon dioxide emissions arise from fossil-fuel burning; the rest arise primarily from deforestation. Chlorofluorocarbons are the second largest contributor to global warming, accounting for about 20% of the total. The third largest contributor is methane, followed by ozone and nitrous oxide. A study of current activities in the US that contribute to global warming shows the following: electric power plants account for about 33% of carbon dioxide emissions; motor vehicles, planes and ships (31%); industrial plants (24%); commercial and residential buildings (11%)

Anthropogenic Warming Impacts on Today's Sierra Nevada Snowpack and Flood Severity

Science.gov (United States)

Huang, X.; Hall, A. D.; Berg, N.

2017-12-01

Focusing on this recent extreme wet year over California, this study investigates the warming impacts on the snowpack and the flood severity over the Sierra Nevada (SN), where the majority of the precipitation occurs during the winter season and early spring. One of our goals is to quantify anthropogenic warming impacts on the snow water equivalent (SWE) including recent historical warming and prescribed future projected warming scenarios; This work also explores to what extent flooding risk has increased under those warming cases. With a good representation of the historical precipitation and snowpack over the Sierra Nevada from the historical reference run at 9km (using WRF), the results from the offline Noah-MP simulations with perturbed near-surface temperatures reveal magnificent impacts of warming to the loss of the average snowpack. The reduction of the SWE under warming mainly results from the decreased rain-to-snow conversion with a weaker effect from increased snowmelt. Compared to the natural case, the past industrial warming decreased the maximum SWE by about one-fifth averaged over the study area. Future continuing warming can result in around one-third reduction of current maximum SWE under RCP4.5 emissions scenario, and the loss can reach to two-thirds under RCP8.5 as a "business-as-usual" condition. The impact of past warming is particularly outstanding over the North SN region where precipitation dominates and over the middle elevation regions where the snow mainly distributes. In the future, the warming impact on SWE progresses to higher regions, and so to the south and east. Under the business-as-usual scenario, the projected mid-elevation snowpack almost disappears by April 1st with even high-elevation snow reduced by about half. Along with the loss of the snowpack, as the temperature warms, floods can also intensify with increased early season runoff especially under heavy-rainy days caused by the weakened rain-to-snow processes and

A Canonical Response in Rainfall Characteristics to Global Warming: Projections by IPCC CMIP5 Models

Science.gov (United States)

Lau, William K. M.; Wu, H. T.; Kim, K. M.

2012-01-01

Changes in rainfall characteristics induced by global warming are examined based on probability distribution function (PDF) analysis, from outputs of 14 IPCC (Intergovernmental Panel on Climate Change), CMIP (5th Coupled Model Intercomparison Project) models under various scenarios of increased CO2 emissions. Results show that collectively CMIP5 models project a robust and consistent global and regional rainfall response to CO2 warming. Globally, the models show a 1-3% increase in rainfall per degree rise in temperature, with a canonical response featuring large increase (100-250 %) in frequency of occurrence of very heavy rain, a reduction (5-10%) of moderate rain, and an increase (10-15%) of light rain events. Regionally, even though details vary among models, a majority of the models (>10 out of 14) project a consistent large scale response with more heavy rain events in climatologically wet regions, most pronounced in the Pacific ITCZ and the Asian monsoon. Moderate rain events are found to decrease over extensive regions of the subtropical and extratropical oceans, but increases over the extratropical land regions, and the Southern Oceans. The spatial distribution of light rain resembles that of moderate rain, but mostly with opposite polarity. The majority of the models also show increase in the number of dry events (absence or only trace amount of rain) over subtropical and tropical land regions in both hemispheres. These results suggest that rainfall characteristics are changing and that increased extreme rainfall events and droughts occurrences are connected, as a consequent of a global adjustment of the large scale circulation to global warming.

Kinematic and dynamic pair collision statistics of sedimenting inertial particles relevant to warm rain initiation

International Nuclear Information System (INIS)

Rosa, Bogdan; Parishani, Hossein; Ayala, Orlando; Wang, Lian-Ping; Grabowski, Wojciech W

2011-01-01

In recent years, direct numerical simulation (DNS) approach has become a reliable tool for studying turbulent collision-coalescence of cloud droplets relevant to warm rain development. It has been shown that small-scale turbulent motion can enhance the collision rate of droplets by either enhancing the relative velocity and collision efficiency or by inertia-induced droplet clustering. A hybrid DNS approach incorporating DNS of air turbulence, disturbance flows due to droplets, and droplet equation of motion has been developed to quantify these effects of air turbulence. Due to the computational complexity of the approach, a major challenge is to increase the range of scales or size of the computation domain so that all scales affecting droplet pair statistics are simulated. Here we discuss our on-going work in this direction by improving the parallel scalability of the code, and by studying the effect of large-scale forcing on pair statistics relevant to turbulent collision. New results at higher grid resolutions show a saturation of pair and collision statistics with increasing flow Reynolds number, for given Kolmogorov scales and small droplet sizes. Furthermore, we examine the orientation dependence of pair statistics which reflects an interesting coupling of gravity and droplet clustering.

Aerosols' influence on the interplay between condensation, evaporation and rain in warm cumulus cloud

Directory of Open Access Journals (Sweden)

O. Altaratz

2008-01-01

Full Text Available A numerical cloud model is used to study the influence of aerosol on the microphysics and dynamics of moderate-sized, coastal, convective clouds that develop under the same meteorological conditions. The results show that polluted convective clouds start their precipitation later and precipitate less than clean clouds but produce larger rain drops. The evaporation process is more significant at the margins of the polluted clouds (compared to the clean cloud due to a higher drop surface area to volume ratio and it is mostly from small drops. It was found that the formation of larger raindrops in the polluted cloud is due to a more efficient collection process.

Music after the rain

CERN Multimedia

2006-01-01

The group Home Cooking (left to right: Jean-Marie Planche, Tony Arnold, Serge Waeffler, Django Manglunki) entertains the crowd with a humoristic blues/rock performance. The earth moved in Prévessin on 29 July. This was not an earthquake but an 'international' music event, the seventeenth CERN Hardronic Festival, which saw musicians from many different countries, including Russia, Britain, Spain, France, Belgium and the USA, take to the stage. The audience rocked to music from eight different groups until the early hours. About a thousand people flocked to CERN to hear what the best of its musical talents had to offer. The evening was very nearly a wash-out, though. After a week of scorching hot temperatures, the heavens suddenly opened and the rain didn't stop until a few minutes before the first act came on stage. Thanks to this narrow escape, the organisers can boast a 17-year run of rain-free Hardronic festivals. All the different musical styles were given a warm reception, from traditional Russian folk...

Global Warming Induced Changes in Rainfall Characteristics in IPCC AR5 Models

Science.gov (United States)

Lau, William K. M.; Wu, Jenny, H.-T.; Kim, Kyu-Myong

2012-01-01

Changes in rainfall characteristic induced by global warming are examined from outputs of IPCC AR5 models. Different scenarios of climate warming including a high emissions scenario (RCP 8.5), a medium mitigation scenario (RCP 4.5), and 1% per year CO2 increase are compared to 20th century simulations (historical). Results show that even though the spatial distribution of monthly rainfall anomalies vary greatly among models, the ensemble mean from a sizable sample (about 10) of AR5 models show a robust signal attributable to GHG warming featuring a shift in the global rainfall probability distribution function (PDF) with significant increase (>100%) in very heavy rain, reduction (10-20% ) in moderate rain and increase in light to very light rains. Changes in extreme rainfall as a function of seasons and latitudes are also examined, and are similar to the non-seasonal stratified data, but with more specific spatial dependence. These results are consistent from TRMM and GPCP rainfall observations suggesting that extreme rainfall events are occurring more frequently with wet areas getting wetter and dry-area-getting drier in a GHG induced warmer climate.

USGS Tracks Acid Rain

Science.gov (United States)

Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

1995-01-01

The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

Acid Rain

Science.gov (United States)

Bricker, Owen P.; Rice, Karen C.

1995-01-01

Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

Optical Rain Gauge Instrument Handbook

Energy Technology Data Exchange (ETDEWEB)

Bartholomew, Mary Jane [Brookhaven National Lab. (BNL), Upton, NY (United States)

2016-04-01

To improve the quantitative description of precipitation processes in climate models, the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility deploys several types of rain gauges (MET, RAIN, and optical rain gauge [ORG] datastreams) as well as disdrometers (DISD and VDIS datastreams) at the Southern Great Plains (SGP) Site. This handbook deals specifically with the independent analog ORG (i.e., the ORG datastream).

Effects of simulated acid rain on soil fauna community composition and their ecological niches.

Science.gov (United States)

Wei, Hui; Liu, Wen; Zhang, Jiaen; Qin, Zhong

2017-01-01

Acid rain is one of the severest environmental issues globally. Relative to other global changes (e.g., warming, elevated atmospheric [CO 2 ], and nitrogen deposition), however, acid rain has received less attention than its due. Soil fauna play important roles in multiple ecological processes, but how soil fauna community responds to acid rain remains less studied. This microcosm experiment was conducted using latosol with simulated acid rain (SAR) manipulations to observe potential changes in soil fauna community under acid rain stress. Four pH levels, i.e., pH 2.5, 3.5, 4.5, and 5.5, and a neutral control of pH 7.0 were set according to the current pH condition and acidification trend of precipitation in southern China. As expected, we observed that the SAR treatments induced changes in soil fauna community composition and their ecological niches in the tested soil; the treatment effects tended to increase as acidity increased. This could be attributable to the environmental stresses (such as acidity, porosity and oxygen supply) induced by the SAR treatments. In addition to direct acidity effect, we propose that potential changes in permeability and movability of water and oxygen in soils induced by acid rain could also give rise to the observed shifts in soil fauna community composition. These are most likely indirect pathways of acid rain to affect belowground community. Moreover, we found that nematodes, the dominating soil fauna group in this study, moved downwards to mitigate the stress of acid rain. This is probably detrimental to soil fauna in the long term, due to the relatively severer soil conditions in the deep than surface soil layer. Our results suggest that acid rain could change soil fauna community and the vertical distribution of soil fauna groups, consequently changing the underground ecosystem functions such as organic matter decomposition and greenhouse gas emissions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Data set: A modeling dataset that spans the rain - snow transition zone: Johnston Draw catchment, Reynolds Creek Experimental Watershed, Idaho, USA

Science.gov (United States)

Hydrometeorological data from the rain-to-snow transition zone in mountain basins are limited. As the climate warms, the transition from rain to snow in mountain regions is moving to higher elevations, and these changes are altering the timing of water delivery to the downstream streams, lakes and w...

Disturbance regimes, gap-demanding trees and seed mass related to tree height in warm temperate rain forests worldwide.

Science.gov (United States)

Grubb, Peter J; Bellingham, Peter J; Kohyama, Takashi S; Piper, Frida I; Valido, Alfredo

2013-08-01

For tropical lowland rain forests, Denslow (1987) hypothesized that in areas with large-scale disturbances tree species with a high demand for light make up a larger proportion of the flora; results of tests have been inconsistent. There has been no test for warm temperate rain forests (WTRFs), but they offer a promising testing ground because they differ widely in the extent of disturbance. WTRF is dominated by microphylls sensu Raunkiaer and has a simpler structure and range of physiognomy than tropical or subtropical rain forests. It occurs in six parts of the world: eastern Asia, New Zealand, Chile, South Africa, SE Australia and the Azores. On the Azores it has been mostly destroyed, so we studied instead the subtropical montane rain forest (STMRF) on the Canary Islands which also represents a relict of the kind of WTRF that once stretched across southern Eurasia. We sought to find whether in these six regions the proportion of tree species needing canopy gaps for establishment reflects the frequency and/or extent of canopy disturbance by wind, landslide, volcanic eruptions (lava flow and ash fall), flood or fire. We used standard floras and ecological accounts to draw up lists of core tree species commonly reaching 5 m height. We excluded species which are very rare, very localized in distribution, or confined to special habitats, e.g. coastal forests or rocky sites. We used published accounts and our own experience to classify species into three groups: (1) needing canopy gaps for establishment; (2) needing either light shade throughout or a canopy gap relatively soon (a few months or years) after establishment; and (3) variously more shade-tolerant. Group 1 species were divided according the kind of canopy opening needed: tree-fall gap, landslide, lava flow, flood or fire. Only some of the significant differences in proportion of Group 1 species were consistent with differences in the extent of disturbance; even in some of those cases other factors seem

Process contributions to the intermodel spread in amplified Arctic warming

Science.gov (United States)

Boeke, R.; Taylor, P. C.

2016-12-01

The Arctic is warming at a rate more than twice the global average. This robust climate system response to an external forcing is referred to as Arctic Amplification (AA). While Coupled Model Intercomparison Project 5 (CMIP5) climate models simulate AA, the largest intermodel spread in projected warming is also found in the Arctic. Quantifying the amount of polar warming relative to global warming influences how society adapts to climate change; a 2°C increase in global mean temperature would result in a polar warming between 4-8°C according to the intermodel spread in CMIP5 simulations. A trove of previous work has considered AA diagnostically using variations in the surface energy budget to attribute the intermodel spread in AA to an assortment of feedbacks—surface albedo, cloud, surface turbulent flux, and atmospheric and oceanic energy transport. We consider a systems-thinking approach treating AA as a process that evolves over time. We hypothesize that two specific components of the AA process are most important and influence the intermodel spread. (1) The inability of the Arctic system to effectively remove excess heat sourced from natural variability. The change in the efficiency of the `Arctic air conditioner' is thought to be due to thinner and less extensive sea ice and the resulting ice albedo feedback. (2) The process through which energy is stored in the ocean and exchanged with the atmosphere within the context of the sea ice annual cycle is also important. This study uses CMIP5 simulations from the historical and RCP8.5 (Representative Concentration Pathway; an emission scenario with forcing increasing to 8.5 W m-2 by 2100) to analyze how the AA process operates in present and future climate. The intermodel spread in these processes and the influence on the spread in AA are discussed. This approach identifies models that more realistically simulate the AA process and will aid in narrowing intermodel spread in Arctic surface temperature

Warming of olive oil processed by high hydrostatic pressure

Czech Academy of Sciences Publication Activity Database

Houška, M.; Kubásek, M.; Strohalm, J.; Landfeld, A.; Kamarád, Jiří

2004-01-01

Roč. 24, č. 2 (2004), s. 303-308 ISSN 0895-7959 R&D Projects: GA MZe EP9026 Keywords : olive oil * food processing * high pressure * warming Subject RIV: GM - Food Processing Impact factor: 0.504, year: 2004

Rain Sensor with Stacked Light Waveguide Having Tilted Air Gap

Directory of Open Access Journals (Sweden)

Kyoo Nam Choi

2014-01-01

Full Text Available Vehicle sensor to detect rain drop on and above waveguide utilizing light deflection and scattering was realized, keeping wide sensing coverage and sensitivity to detect mist accumulation. Proposed sensor structure under stacked light wave guide consisted of light blocking fixture surrounding photodetector and adjacent light source. Tilted air gap between stacked light waveguide and light blocking fixture played major role to increase sensitivity and to enhance linearity. This sensor structure eliminated complex collimating optics, while keeping wide sensing coverage using simple geometry. Detection algorithm based on time-to-intensity transformation process was used to convert raining intensity into countable raining process. Experimental result inside simulated rain chamber showed distinct different response between light rain and normal rain. Application as automobile rain sensor is expected.

The effect of aerosol-derived changes in the warm phase on the properties of deep convective clouds

Science.gov (United States)

Chen, Qian; Koren, Ilan; Altaratz, Orit; Heiblum, Reuven; Dagan, Guy

2017-04-01

The aerosol impact on deep convective clouds starts in an increased number of cloud droplets in higher aerosol loading environment. This change drives many others, like enhanced condensational growth, delay in collision-coalescence and others. Since the warm processes serve as the initial and boundary conditions for the mixed and cold-phase processes in deep clouds, it is highly important to understand the aerosol effect on them. The weather research and forecasting model (WRF) with spectral bin microphysics was used to study a deep convective system over the Marshall Islands, during the Kwajalein Experiment (KWAJEX). Three simulations were conducted with aerosol concentrations of 100, 500 and 2000 cm-3, to reflect clean, semipolluted, and polluted conditions. The results of the clean run agreed well with the radar profiles and rain rate observations. The more polluted simulations resulted in larger total cloud mass, larger upper level cloud fraction and rain rates. There was an increased mass both below and above the zero temperature level. It indicates of more efficient growth processes both below and above the zero level. In addition the polluted runs showed an increased upward transport (across the zero level) of liquid water due to both stronger updrafts and larger droplet mobility. In this work we discuss the transport of cloud mass crossing the zero temperature level (in both directions) in order to gain a process level understanding of how aerosol effects on the warm processes affect the macro- and micro-properties of deep convective clouds.

Prediction Method for Rain Rate and Rain Propagation Attenuation for K-Band Satellite Communications Links in Tropical Areas

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Baso Maruddani

2015-01-01

Full Text Available This paper deals with the prediction method using hidden Markov model (HMM for rain rate and rain propagation attenuation for K-band satellite communication link at tropical area. As is well known, the K-band frequency is susceptible of being affected by atmospheric condition, especially in rainy condition. The wavelength of K-band frequency which approaches to the size of rain droplet causes the signal strength is easily attenuated and absorbed by the rain droplet. In order to keep the quality of system performance for K-band satellite communication link, therefore a special attention has to be paid for rain rate and rain propagation attenuation. Thus, a prediction method for rain rate and rain propagation attenuation based on HMM is developed to process the measurement data. The measured and predicted data are then compared with the ITU-R recommendation. From the result, it is shown that the measured and predicted data show similarity with the model of ITU-R P.837-5 recommendation for rain rate and the model of ITU-R P.618-10 recommendation for rain propagation attenuation. Meanwhile, statistical data for measured and predicted data such as fade duration and interfade duration have insignificant discrepancy with the model of ITU-R P.1623-1 recommendation.

Impaired ecosystem process despite little effects on populations: modeling combined effects of warming and toxicants.

Science.gov (United States)

Galic, Nika; Grimm, Volker; Forbes, Valery E

2017-08-01

Freshwater ecosystems are exposed to many stressors, including toxic chemicals and global warming, which can impair, separately or in combination, important processes in organisms and hence higher levels of organization. Investigating combined effects of warming and toxicants has been a topic of little research, but neglecting their combined effects may seriously misguide management efforts. To explore how toxic chemicals and warming, alone and in combination, propagate across levels of biological organization, including a key ecosystem process, we developed an individual-based model (IBM) of a freshwater amphipod detritivore, Gammarus pseudolimnaeus, feeding on leaf litter. In this IBM, life history emerges from the individuals' energy budgets. We quantified, in different warming scenarios (+1-+4 °C), the effects of hypothetical toxicants on suborganismal processes, including feeding, somatic and maturity maintenance, growth, and reproduction. Warming reduced mean adult body sizes and population abundance and biomass, but only in the warmest scenarios. Leaf litter processing, a key contributor to ecosystem functioning and service delivery in streams, was consistently enhanced by warming, through strengthened interaction between the detritivorous consumer and its resource. Toxicant effects on feeding and maintenance resulted in initially small adverse effects on consumers, but ultimately led to population extinction and loss of ecosystem process. Warming in combination with toxicants had little effect at the individual and population levels, but ecosystem process was impaired in the warmer scenarios. Our results suggest that exposure to the same amount of toxicants can disproportionately compromise ecosystem processing depending on global warming scenarios; for example, reducing organismal feeding rates by 50% will reduce resource processing by 50% in current temperature conditions, but by up to 200% with warming of 4 °C. Our study has implications for

The Indo-Pacific Warm Pool: critical to world oceanography and world climate

Science.gov (United States)

De Deckker, Patrick

2016-12-01

The Indo-Pacific Warm Pool holds a unique place on the globe. It is a large area [>30 × 106 km2] that is characterised by permanent surface temperature >28 °C and is therefore called the `heat engine' of the globe. High convective clouds which can reach altitudes up to 15 km generate much latent heat in the process of convection and this area is therefore called the `steam engine' of the world. Seasonal and contrasting monsoonal activity over the region is the cause for a broad seasonal change of surface salinities, and since the area lies along the path of the Great Ocean Conveyor Belt, it is coined the `dilution' basin due to the high incidence of tropical rain and, away from the equator, tropical cyclones contribute to a significant drop in sea water salinity. Discussion about what may happen in the future of the Warm Pool under global warming is presented together with a description of the Warm Pool during the past, such as the Last Glacial Maximum when sea levels had dropped by ~125 m. A call for urgent monitoring of the IPWP area is justified on the grounds of the significance of this area for global oceanographic and climatological processes, but also because of the concerned threats to human population living there.

Improved Micro Rain Radar snow measurements using Doppler spectra post-processing

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M. Maahn

2012-11-01

Full Text Available The Micro Rain Radar 2 (MRR is a compact Frequency Modulated Continuous Wave (FMCW system that operates at 24 GHz. The MRR is a low-cost, portable radar system that requires minimum supervision in the field. As such, the MRR is a frequently used radar system for conducting precipitation research. Current MRR drawbacks are the lack of a sophisticated post-processing algorithm to improve its sensitivity (currently at +3 dBz, spurious artefacts concerning radar receiver noise and the lack of high quality Doppler radar moments. Here we propose an improved processing method which is especially suited for snow observations and provides reliable values of effective reflectivity, Doppler velocity and spectral width. The proposed method is freely available on the web and features a noise removal based on recognition of the most significant peak. A dynamic dealiasing routine allows observations even if the Nyquist velocity range is exceeded. Collocated observations over 115 days of a MRR and a pulsed 35.2 GHz MIRA35 cloud radar show a very high agreement for the proposed method for snow, if reflectivities are larger than −5 dBz. The overall sensitivity is increased to −14 and −8 dBz, depending on range. The proposed method exploits the full potential of MRR's hardware and substantially enhances the use of Micro Rain Radar for studies of solid precipitation.

Rain intensity over specific rain thresholds in Athens and Thessaloniki, Greece

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Philandras, C. M.; Nastos, P. T.; Kapsomenakis, J.; Repapis, C. C.

2009-09-01

It is well documented that climatic change has caused significant impacts in the water cycle and great spatial and temporal variability of the rain events. The rain scarcity in many cases is associated with extreme convective weather resulted in flash floods, which threatens the human life and the existed infrastructure. In this study, the annual mean rain intensity (mm/h) along with the annual number of rain days for rain events over specific rain thresholds, such as 10, 20, 30, 40, 50 mm, in two Greek cities Athens and Thessaloniki, during the period 1930-2007, are examined. The meteorological data, which concern daily rain totals (mm) and duration (h), were acquired from the National Observatory of Athens and from the meteorological station of the University of Thessaloniki. Our findings show that, in Athens, an increase in the number of annual rain days and the mean rain intensity over the aforementioned rain thresholds appears at the end of 1980’s and continues until nowadays. On the contrary, concerning Thessaloniki, a decrease in the rain days is apparent from 1980, while the decrease in the mean rain intensity concerns only the rain thresholds of 10 and 20 mm. This analysis reveals that extreme rain events are more frequent in Athens, which is under a high urbanization rhythm, than in Thessaloniki at the north of Greece. Finally, the patterns of the atmospheric circulation, which are associated with specific extreme cases are analysed, using NCEP reanalysis data.

analysis of rain rate and rain attenuation for earth-space

African Journals Online (AJOL)

Rain rate and rain attenuation predictions are vital when designing microwave satellite and terrestrial communication links, such as in the Ku and Ka bands. This paper presents the cumulative distribution functions (CDFs) of the predicted rain rate and rain attenuation for Uyo, Akwa Ibom State (AKS) (Latitude: 4.88°N, ...

Time-dependent, non-monotonic response of warm convective cloud fields to changes in aerosol loading

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G. Dagan

2017-06-01

Full Text Available Large eddy simulations (LESs with bin microphysics are used here to study cloud fields' sensitivity to changes in aerosol loading and the time evolution of this response. Similarly to the known response of a single cloud, we show that the mean field properties change in a non-monotonic trend, with an optimum aerosol concentration for which the field reaches its maximal water mass or rain yield. This trend is a result of competition between processes that encourage cloud development versus those that suppress it. However, another layer of complexity is added when considering clouds' impact on the field's thermodynamic properties and how this is dependent on aerosol loading. Under polluted conditions, rain is suppressed and the non-precipitating clouds act to increase atmospheric instability. This results in warming of the lower part of the cloudy layer (in which there is net condensation and cooling of the upper part (net evaporation. Evaporation at the upper part of the cloudy layer in the polluted simulations raises humidity at these levels and thus amplifies the development of the next generation of clouds (preconditioning effect. On the other hand, under clean conditions, the precipitating clouds drive net warming of the cloudy layer and net cooling of the sub-cloud layer due to rain evaporation. These two effects act to stabilize the atmospheric boundary layer with time (consumption of the instability. The evolution of the field's thermodynamic properties affects the cloud properties in return, as shown by the migration of the optimal aerosol concentration toward higher values.

Scale Dependence of Spatiotemporal Intermittence of Rain

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Kundu, Prasun K.; Siddani, Ravi K.

2011-01-01

It is a common experience that rainfall is intermittent in space and time. This is reflected by the fact that the statistics of area- and/or time-averaged rain rate is described by a mixed distribution with a nonzero probability of having a sharp value zero. In this paper we have explored the dependence of the probability of zero rain on the averaging space and time scales in large multiyear data sets based on radar and rain gauge observations. A stretched exponential fannula fits the observed scale dependence of the zero-rain probability. The proposed formula makes it apparent that the space-time support of the rain field is not quite a set of measure zero as is sometimes supposed. We also give an ex.planation of the observed behavior in tenus of a simple probabilistic model based on the premise that rainfall process has an intrinsic memory.

Promotion of Scientific Literacy on Global Warming by Process Drama

Science.gov (United States)

Pongsophon, Pongprapan; Yutakom, Naruemon; Boujaoude, Saouma B.

2010-01-01

This project aims to investigate how process drama promotes scientific literacy in the context of global warming. Thirty-one lower (n = 24) and upper (n = 7) secondary students of one secondary school in Bangkok, Thailand participated in a seven-day workshop which process drama strategy was implemented. In the workshop, the students were actively…

Factors Contributing to the Hydrologic Effectiveness of a Rain Garden Network (Cincinnati OH USA

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William D. Shuster

2017-09-01

Full Text Available Infiltrative rain gardens can add retention capacity to sewersheds, yet factors contributing to their capacity for detention and redistribution of stormwater runoff are dynamic and often unverified. Over a four-year period, we tracked whole-system water fluxes in a two-tier rain garden network and assessed near-surface hydrology and soil development across construction and operational phases. The monitoring data provided a quantitative basis for determining effectiveness of this stormwater control measure. Based on 233 monitored warm-season rainfall events, nearly half of total inflow volume was detained, with 90 percent of all events producing no flow to the combined sewer. For the events that did result in flow to the combined sewer system, the rain garden delayed flows for an average of 5.5 h. Multivariate analysis of hydrologic fluxes indicated that total event rainfall depth was a predominant hydrologic driver for network outflow during both phases, with average event intensity and daily evapotranspiration as additional, independent factors in regulating retention in the operational phase. Despite sediment loads that can clog the rooting zone, and overall lower-than-design infiltration rates, tradeoffs among soil profile development and hydrology apparently maintained relatively high overall retention effectiveness. Overall, our study identified factors relevant to regulation of retention capacity of a rain garden network. These factors may be generalizable, and guide improvement of new or existing rain garden designs.

Neutral rains at Athens, Greece: a natural safeguard against acidification of rains

International Nuclear Information System (INIS)

Kita, Itsuro; Sato, Takayuki; Kase, Yoshinori; Mitropoulos, Panagiotis

2004-01-01

Samples of all rains in a period from October, 1998 to January, 1999 at Athens, Greece, were collected. The pH values of almost all of these rains clustered in a high range of 7.0-7.5, with no relation between pH and their SO 4 2- , NO 3 - and Cl - contents. In addition, a few rains with low contents of chemical components similar to pure water also were observed, giving a pH (approx. 5.5) of rain caused by dissolution of only atmospheric CO 2 in it. These results indicate that the level of air pollution of Athens by human activity has become lower during the last decade, restoring the neutral condition of rain in this area. Furthermore, the Ca contents and Ca/Mg ratios in these rains, as well as their chemical and isotopic behavior, suggest that particles of calcium carbonate taken in as dust act as a neutralizer of rains. The dust must be derived not only from the urban area of Athens but also from its environs or areas distant from it. Such a mechanism causing universally neutral rains throughout the rainy season at Athens must have worked as a natural safeguard against rains acidified naturally and artificially from ancient times up to recent years, keeping the remains of ancient Greece in a good state of preservation during such a long period

Large-scale modeling of rain fields from a rain cell deterministic model

Science.gov (United States)

FéRal, Laurent; Sauvageot, Henri; Castanet, Laurent; Lemorton, JoëL.; Cornet, FréDéRic; Leconte, Katia

2006-04-01

A methodology to simulate two-dimensional rain rate fields at large scale (1000 × 1000 km2, the scale of a satellite telecommunication beam or a terrestrial fixed broadband wireless access network) is proposed. It relies on a rain rate field cellular decomposition. At small scale (˜20 × 20 km2), the rain field is split up into its macroscopic components, the rain cells, described by the Hybrid Cell (HYCELL) cellular model. At midscale (˜150 × 150 km2), the rain field results from the conglomeration of rain cells modeled by HYCELL. To account for the rain cell spatial distribution at midscale, the latter is modeled by a doubly aggregative isotropic random walk, the optimal parameterization of which is derived from radar observations at midscale. The extension of the simulation area from the midscale to the large scale (1000 × 1000 km2) requires the modeling of the weather frontal area. The latter is first modeled by a Gaussian field with anisotropic covariance function. The Gaussian field is then turned into a binary field, giving the large-scale locations over which it is raining. This transformation requires the definition of the rain occupation rate over large-scale areas. Its probability distribution is determined from observations by the French operational radar network ARAMIS. The coupling with the rain field modeling at midscale is immediate whenever the large-scale field is split up into midscale subareas. The rain field thus generated accounts for the local CDF at each point, defining a structure spatially correlated at small scale, midscale, and large scale. It is then suggested that this approach be used by system designers to evaluate diversity gain, terrestrial path attenuation, or slant path attenuation for different azimuth and elevation angle directions.

More rain compensation results

Science.gov (United States)

Sworder, D. D.; Vojak, R.

1992-01-01

To reduce the impact of rain-induced attenuation in the 20/30 GHz band, the attenuation at a specified signal frequency must be estimated and extrapolated forward in time on the basis of a noisy beacon measurement. Several studies have used model based procedures for solving this problem in statistical inference. Perhaps the most widely used model-based paradigm leads to the Kalman filter and its lineal variants. In this formulation, the dynamic features of the attenuation are represented by a state process (x(sub t)). The observation process (y(sub t)) is derived from beacon measurements. Some ideas relating to the signal processing problems related to uplink power control are presented. It is shown that some easily implemented algorithms hold promise for use in estimating rain induced fades. The algorithms were applied to actual data generated at the Virginia Polytechnic Institute and State University (VPI) test facility. Because only one such event was studied, it is not clear that the algorithms will have the same effectiveness when a wide range of events are studied.

Performance analysis of spring wheat genotypes under rain-fed conditions in warm humid environment of Nepal

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Ramesh Raj Puri

2015-06-01

Full Text Available Around 25% of total wheat area in Terai of Nepal falls under rain-fed and partially irrigated condition. A Coordinated varietal trial (CVT was conducted during two consecutive crop cycles (2011-12 and 2012-13 under timely sown rain-fed conditions of Terai. The trial was conducted in Alpha Lattice design with two replications at Nepal Agricultural Research Council, National Wheat Research Program, Bhairahawa and Nepal Agricultural Research Council, Regional Agriculture Research Station, Nepalgunj. Observations were recorded for yield and yield traits and analyzed using statistical software Cropstat 7.2.The combined analysis of coordinated varietal trial showed that BL 3978 possessed the highest yield (2469.2 Kg ha-1 followed by NL 1097 (2373.2 Kg ha-1 and NL 1094 (2334.06 Kg ha-1. Genotype x Environment interaction for grain yield was significant (p<0.05 over locations and years. BL 3978 with early maturity (111 days escaped the heat stress environment. Among the top three genotypes, BL 3978 was consistently higher in both favorable and unfavorable conditions. Earliness was one of the major traits for heat tolerant genotypes. The three identified genotypes will be further evaluated in participatory varietal selection or coordinated farmers field trial followed by small plot seed multiplication (seed increase and release in the future for timely sown rain-fed conditions. These lines also appear suitable for inclusion in crossing program targeted for water stress tolerance variety development. DOI: http://dx.doi.org/10.3126/ije.v4i2.12649 International Journal of Environment Vol.4(2 2015: 289-295

[Relationship between atmospheric particles and rain water chemistry character].

Science.gov (United States)

Huo, Ming-Qun; Sun, Qian; Xie, Peng; Bai, Yu-Hua; Liu, Zhao-Rong; Li, Ji-Long; Lu, Si-Hua

2009-11-01

Rain and atmospheric particle samples were collected in the rural area of Taian and Shenzhen in 2007, respectively. Rain sampling was carried out during the precipitation process and several samples were got from the beginning of one precipitation to the end. The chemical character changes during precipitation and the changes of concentration of particles before and after rain were studied in this research to understand the contribution of particles on the rain chemical character and the rain-out effect for particles. The volume-weighted mean pH of rainwater in Taian was 5.97 and the total concentration of ions was 1 187.96 microeq x L(-1). The mass concentration of PM10 in Taian was 131.76 microg/m3 and that of PM2.5 was 103.84 microg/m3. The volume-weighted mean pH of rainwater in Shenzhen was 4.72 and the total concentration of ions was 175.89 microeq x L(-1). The mass concentration of PM10 in Shenzhen was 56.66 microg/m3 and that of PM2.5 was 41.52 microg/m3. During precipitation process pH and ion concentration of rain decrease and it is shown the neutralizing effect happens. The difference between rainwater of Taian and Shenzhen is due to cloud water acidity, atmospheric particles character and atmospheric acid-basic gases concentration. The clean-up effect of Na+ and Ca2+ by rain is high and which of NH4+ and NO3- is low. The clean-up effect for mass concentration, ions concentration and element concentration of particles by rain are significant.

Understanding Acid Rain

Science.gov (United States)

Damonte, Kathleen

2004-01-01

The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

Heavy rain effects

Science.gov (United States)

Dunham, R. Earl, Jr.

1994-01-01

This paper summarizes the current state of knowledge of the effect of heavy rain on airplane performance. Although the effects of heavy rain on airplane systems and engines are generally known, only recently has the potential aerodynamic effect of heavy rain been recognized. In 1977 the United States Federal Aviation Administration (FAA) conducted a study of 25 aircraft accidents and incidents which occurred between 1964 and 1976 in which low-altitude wind shear could have been a contributing factor. Of the 25 cases (23 approach or landing and 2 take-off) in the study, ten cases had occurred in a rain environment, and in five cases these were classified as intense or heavy rain encounters. These results led to the reconsideration of high-intensity, short-duration rainfall as a potential weather-related aircraft safety hazard, particularly in the take-off and/or approach phases of flight.

Effects of intermittent acid rain on proline and antioxidant content on medicinal plant “Pereskia bleo”

Science.gov (United States)

Sulandjari; Dewi, W. S.

2018-03-01

Global warming due to CO2 and other greenhouse gas emissions from human activities have led to climate change and environmental degradation. The acid rain, with the pH of rainwater below 5.6, is a serious environmental problem. Arising from air pollution and potentially harmful to health, it can damage old buildings and distract the growth and physiological metabolism of sensitive plants. How does the influence of climate change on medicinal plants such as Pereskia bleo? The leaf of Pereskia bleo (Kunth) DC. contains high antioxidants with benefits for anti-cancer, anti-tumor, anti-rheumatic, and anti-inflammatory. This research aims to investigate the influence of acid rain on the proline level and antioxidant content of Pereskia bleo. Having been carried out from June to August in Jogjakarta, this study was conducted through the use of artificial acid rain with pH 5.8, 4.9, 3.7 and 2.9, by adding sulfate acid (H2SO4) to rainwater. The interval of intermittent watering acid rain to the plants is once a day, twice a day, and once in three days with three replications for six weeks. The results showed that Acid rain with a pH less than 4.9 and the intermittent interval of acid rain twice a day and once in three days significantly suppresses growth and chlorophyll content. In contrast, it increases the proline and antioxidant levels as a tolerant action of the plant.

A Rain Taxonomy for Degraded Visual Environment Mitigation

Science.gov (United States)

Gatlin, P. N.; Petersen, W. A.

2018-01-01

This Technical Memorandum (TM) provides a description of a rainfall taxonomy that defines the detailed characteristics of naturally occurring rainfall. The taxonomy is based on raindrop size measurements collected around the globe and encompasses several different climate types. Included in this TM is a description of these rainfall observations, an explanation of methods used to process those data, and resultant metrics comprising the rain taxonomy database. Each of the categories in the rain taxonomy are characterized by a unique set of raindrop sizes that can be used in simulations of electromagnetic wave propagation through a rain medium.

Warm Cleanup of Coal-Derived Syngas: Multicontaminant Removal Process Demonstration

Energy Technology Data Exchange (ETDEWEB)

Spies, Kurt A.; Rainbolt, James E.; Li, Xiaohong S.; Braunberger, Beau; Li, Liyu; King, David L.; Dagle, Robert A.

2017-02-15

Warm cleanup of coal- or biomass-derived syngas requires sorbent and catalytic beds to protect downstream processes and catalysts from fouling. Sulfur is particularly harmful because even parts-per-million amounts are sufficient to poison downstream synthesis catalysts. Zinc oxide (ZnO) is a conventional sorbent for sulfur removal; however, its operational performance using real gasifier-derived syngas and in an integrated warm cleanup process is not well reported. In this paper, we report the optimal temperature for bulk desulfurization to be 450oC, while removal of sulfur to parts-per-billion levels requires a lower temperature of approximately 350oC. Under these conditions, we found that sulfur in the form of both hydrogen sulfide and carbonyl sulfide could be absorbed equally well using ZnO. For long-term operation, sorbent regeneration is desirable to minimize process costs. Over the course of five sulfidation and regeneration cycles, a ZnO bed lost about a third of its initial sulfur capacity, however sorbent capacity stabilized. Here, we also demonstrate, at the bench-scale, a process and materials used for warm cleanup of coal-derived syngas using five operations: 1) Na2CO3 for HCl removal, 2) regenerable ZnO beds for bulk sulfur removal, 3) a second ZnO bed for trace sulfur removal, 4) a Ni-Cu/C sorbent for multi-contaminant inorganic removal, and 5) a Ir-Ni/MgAl2O4 catalyst employed for ammonia decomposition and tar and light hydrocarbon steam reforming. Syngas cleanup was demonstrated through successful long-term performance of a poison-sensitive, Cu-based, water-gas-shift catalyst placed downstream of the cleanup process train. The tar reformer is an important and necessary operation with this particular gasification system; its inclusion was the difference between deactivating the water-gas catalyst with carbon deposition and successful 100-hour testing using 1 LPM of coal-derived syngas.

Using wireless sensor networks to improve understanding of rain-on-snow events across the Sierra Nevada

Science.gov (United States)

Maurer, T.; Avanzi, F.; Oroza, C.; Malek, S. A.; Glaser, S. D.; Bales, R. C.; Conklin, M. H.

2017-12-01

We use data gathered from Wireless Sensor Networks (WSNs) between 2008 and 2017 to investigate the temporal/spatial patterns of rain-on-snow events in three river basins of California's Sierra Nevada. Rain-on-snow transitions occur across a broad elevation range (several hundred meters), both between storms and within a given storm, creating an opportunity to use spatially and temporally dense data to forecast and study them. WSNs collect snow depth; meteorological data; and soil moisture and temperature data across relatively dense sensor clusters. Ten to twelve measurement nodes per cluster are placed across 1-km2 areas in locations representative of snow patterns at larger scales. Combining precipitation and snow data from snow-pillow and climate stations with an estimation of dew-point temperature from WSNs, we determine the frequency, timing, and geographic extent of rain-on-snow events. We compare these results to WSN data to evaluate the impact of rain-on-snow events on snowpack energy balance, density, and depth as well as on soil moisture. Rain-on-snow events are compared to dry warm-weather days to identify the relative importance of rain and radiation as the primary energy input to the snowpack for snowmelt generation. An intercomparison of rain-on-snow events for the WSNs in the Feather, American, and Kings River basins captures the behavior across a 2° latitudinal range of the Sierra Nevada. Rain-on-snow events are potentially a more important streamflow generation mechanism in the lower-elevation Feather River basin. Snowmelt response to rain-on-snow events changes throughout the wet season, with later events resulting in more melt due to snow isothermal conditions, coarser grain size, and more-homogeneous snow stratigraphy. Regardless of snowmelt response, rain-on-snow events tend to result in decreasing snow depth and a corresponding increase in snow density. Our results demonstrate that strategically placed WSNs can provide the necessary data at

Recognition of people with an opinion that nuclear power generation causes global warming

International Nuclear Information System (INIS)

Fukue, Chiyokazu

2004-01-01

Almost a half of the people are thinking that nuclear power generation causes global warming. We conducted a survey in order to explore the recognition and background for the thinking of people. Consequently, the existence of the right knowledge ''nuclear power generation does not discharge carbon dioxide at the time of power generation'' influenced most the idea which nuclear power generation prevents global warming. On the other hand, the misunderstanding as ''the radioactive material produced from a nuclear power plant advances global warming'' has influenced the idea considered as a cause, and it is though that this misunderstanding depend on the negative image to nuclear power generation. Moreover, many people do not recognize the mechanism of global warming, and it is thought that they confuse global warming with the other global environment problems, such as acid rain or ozone layer destruction. Therefore, it is required to spread the knowledge that nuclear power generation does not discharge carbon dioxide, and to promote the understanding that a radioactive material is not related to global warming. Furthermore, it is required to distinguish global warming from the other global environment problems, and to explain them intelligibly. (author)

An Uncertainty Data Set for Passive Microwave Satellite Observations of Warm Cloud Liquid Water Path

Science.gov (United States)

Greenwald, Thomas J.; Bennartz, Ralf; Lebsock, Matthew; Teixeira, João.

2018-04-01

The first extended comprehensive data set of the retrieval uncertainties in passive microwave observations of cloud liquid water path (CLWP) for warm oceanic clouds has been created for practical use in climate applications. Four major sources of systematic errors were considered over the 9-year record of the Advanced Microwave Scanning Radiometer-EOS (AMSR-E): clear-sky bias, cloud-rain partition (CRP) bias, cloud-fraction-dependent bias, and cloud temperature bias. Errors were estimated using a unique merged AMSR-E/Moderate resolution Imaging Spectroradiometer Level 2 data set as well as observations from the Cloud-Aerosol Lidar with Orthogonal Polarization and the CloudSat Cloud Profiling Radar. To quantify the CRP bias more accurately, a new parameterization was developed to improve the inference of CLWP in warm rain. The cloud-fraction-dependent bias was found to be a combination of the CRP bias, an in-cloud bias, and an adjacent precipitation bias. Globally, the mean net bias was 0.012 kg/m2, dominated by the CRP and in-cloud biases, but with considerable regional and seasonal variation. Good qualitative agreement between a bias-corrected AMSR-E CLWP climatology and ship observations in the Northeast Pacific suggests that the bias estimates are reasonable. However, a possible underestimation of the net bias in certain conditions may be due in part to the crude method used in classifying precipitation, underscoring the need for an independent method of detecting rain in warm clouds. This study demonstrates the importance of combining visible-infrared imager data and passive microwave CLWP observations for estimating uncertainties and improving the accuracy of these observations.

Rain attenuation studies from radiometric and rain DSD measurements at two tropical locations

Science.gov (United States)

Halder, Tuhina; Adhikari, Arpita; Maitra, Animesh

2018-05-01

Efficient use of satellite communication in tropical regions demands proper characterization of rain attenuation, particularly, in view of the available popular propagation models which are mostly based on temperate climatic data. Thus rain attenuations at frequencies 22.234, 23.834 and 31.4/30 GHz over two tropical locations Kolkata (22.57°N, 88.36°E, India) and Belem (1.45°S, 48.49° W, Brazil), have been estimated for the year 2010 and 2011, respectively. The estimation has been done utilizing ground-based disdrometer observations and radiometric measurements over Earth-space path. The results show that rain attenuation estimations from radiometric data are reliable only at low rain rates (measurements show good agreement with the ITU-R model, even at high rain rates (upto100 mm/h). Despite having significant variability in terms of drop size distribution (DSD), the attenuation values calculated from DSD data (disdrometer measurements) at Kolkata and Belem differ a little for the rain rates below 30 mm/h. However, the attenuation values, obtained from radiometric measurements at the two places, show significant deviations ranging from 0.54 dB to 3.2 dB up to a rain rate of 30 mm/h, on account of different rain heights, mean atmospheric temperatures and climatology of the two locations.

Understanding the formation and evolution of rain-formed fresh lenses at the ocean surface

Science.gov (United States)

Drushka, Kyla; Asher, William E.; Ward, Brian; Walesby, Kieran

2016-04-01

Rain falling on the ocean produces a layer of buoyant fresher surface water, or "fresh lens." Fresh lenses can have significant impacts on satellite-in situ salinity comparisons and on exchanges between the surface and the bulk mixed layer. However, because these are small, transient features, relatively few observations of fresh lenses have been made. Here the Generalized Ocean Turbulence Model (GOTM) is used to explore the response of the upper few meters of the ocean to rain events. Comparisons with observations from several platforms demonstrate that GOTM can reproduce the main characteristics of rain-formed fresh lenses. Idealized sensitivity tests show that the near-surface vertical salinity gradient within fresh lenses has a linear dependence on rain rate and an inverse dependence on wind speed. Yearlong simulations forced with satellite rainfall and reanalysis atmospheric parameters demonstrate that the mean salinity difference between 0.01 and 5 m, equivalent to the measurement depths of satellite radiometers and Argo floats, is -0.04 psu when averaged over the 20°S-20°N tropical band. However, when averaged regionally, the mean vertical salinity difference exceeds -0.15 psu in the Indo-Pacific warm pool, in the Pacific and Atlantic intertropical convergence zone, and in the South Pacific convergence zone. In most of these regions, salinities measured by the Aquarius satellite instrument have a fresh bias relative to Argo measurements at 5 m depth. These results demonstrate that the fresh bias in Aquarius salinities in rainy, low-wind regions may be caused by the presence of rain-produced fresh lenses.

Applying super-droplets as a compact representation of warm-rain microphysics for aerosol-cloud-aerosol interactions

Science.gov (United States)

Arabas, S.; Jaruga, A.; Pawlowska, H.; Grabowski, W. W.

2012-12-01

Clouds may influence aerosol characteristics of their environment. The relevant processes include wet deposition (rainout or washout) and cloud condensation nuclei (CCN) recycling through evaporation of cloud droplets and drizzle drops. Recycled CCN physicochemical properties may be altered if the evaporated droplets go through collisional growth or irreversible chemical reactions (e.g. SO2 oxidation). The key challenge of representing these processes in a numerical cloud model stems from the need to track properties of activated CCN throughout the cloud lifecycle. Lack of such "memory" characterises the so-called bulk, multi-moment as well as bin representations of cloud microphysics. In this study we apply the particle-based scheme of Shima et al. 2009. Each modelled particle (aka super-droplet) is a numerical proxy for a multiplicity of real-world CCN, cloud, drizzle or rain particles of the same size, nucleus type,and position. Tracking cloud nucleus properties is an inherent feature of the particle-based frameworks, making them suitable for studying aerosol-cloud-aerosol interactions. The super-droplet scheme is furthermore characterized by linear scalability in the number of computational particles, and no numerical diffusion in the condensational and in the Monte-Carlo type collisional growth schemes. The presentation will focus on processing of aerosol by a drizzling stratocumulus deck. The simulations are carried out using a 2D kinematic framework and a VOCALS experiment inspired set-up (see http://www.rap.ucar.edu/~gthompsn/workshop2012/case1/).

Short-term exposure to warm microhabitats could explain amphibian persistence with Batrachochytrium dendrobatidis.

Science.gov (United States)

Daskin, Joshua H; Alford, Ross A; Puschendorf, Robert

2011-01-01

Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although the species is recolonizing many sites, no population has fully recovered. Litoria lorica disappeared from all known sites in the early 1990 s and was thought globally extinct, but a new population was discovered in 2008, in an upland dry forest habitat it shares with L. nannotis. All frogs of both species observed during three population censuses were apparently healthy, but most carried Bd. Frogs perch on sun-warmed rocks in dry forest streams, possibly keeping Bd infections below the lethal threshold attained in cooler rain forests. We tested whether short-term elevated temperatures can hamper Bd growth in vitro over one generation (four days). Simulating the temperatures available to frogs on strongly and moderately warmed rocks in dry forests, by incubating cultures at 33°C for one hour daily, reduced Bd growth below that of Bd held at 15°C constantly (representing rain forest habitats). Even small decreases in the exponential growth rate of Bd on hosts may contribute to the survival of frogs in dry forests.

Short-term exposure to warm microhabitats could explain amphibian persistence with Batrachochytrium dendrobatidis.

Directory of Open Access Journals (Sweden)

Joshua H Daskin

Full Text Available Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd, but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although the species is recolonizing many sites, no population has fully recovered. Litoria lorica disappeared from all known sites in the early 1990 s and was thought globally extinct, but a new population was discovered in 2008, in an upland dry forest habitat it shares with L. nannotis. All frogs of both species observed during three population censuses were apparently healthy, but most carried Bd. Frogs perch on sun-warmed rocks in dry forest streams, possibly keeping Bd infections below the lethal threshold attained in cooler rain forests. We tested whether short-term elevated temperatures can hamper Bd growth in vitro over one generation (four days. Simulating the temperatures available to frogs on strongly and moderately warmed rocks in dry forests, by incubating cultures at 33°C for one hour daily, reduced Bd growth below that of Bd held at 15°C constantly (representing rain forest habitats. Even small decreases in the exponential growth rate of Bd on hosts may contribute to the survival of frogs in dry forests.

Long-period polar rain variations, solar wind and hemispherically symmetric polar rain

International Nuclear Information System (INIS)

Makita, K.; Meng, C.

1987-01-01

On the basic of electron data obtained by the Defense Meteorological Satellite Program (DMSP) F2 satellite the long-period variations of the polar rain flux are examined for four consecutive solar rotations. It is clearly demonstrated that the asymmetric enhancement of the polar rain flux is strongly controlled by the sector structure of the interplanetary magnetic field (IMF). However, the orbit-to-orbit and day-to-day variations of the polar rain flux are detected even during a very stable sector period, and the polar rain flux does not have any clear relationship to the magnitude of the IMF B/sub x/ or B/sub y/. Thus the polarity of B/sub x/ controls only the accessibility of a polar region. It is also noticed that the intensity of polar rain fluxes does not show any relationship to the density of the solar wind, suggesting that the origin of the polar rain electrons is different from the commonly observed part of the solar wind electron distribution function. In addition to the asymmetric polar rain distribution, increasing polar rain fluxes of similar high intensity are sometimes detected over both polar caps. An examination of more than 1 year's data from the DMSP F2 and F4 satellites shows that simultaneous intense uniform precipitations (>10 7 electrons/cm 2 s sr) over both polar caps are not coincidental; it also shows that the spectra are similar. The occurrence of hemispherically symmetric events is not common. They generally are observed after an IMF sector transition period, during unstable periods in the sector structure, and while the solar wind density is high. copyright American Geophysical Union 1987

The Acid Rain Reader.

Science.gov (United States)

Stubbs, Harriett S.; And Others

A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

Acid Rain Study Guide.

Science.gov (United States)

Hunger, Carolyn; And Others

Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

Oceanic temperate forest versus warm temperate rainforest: a reply to Grubb et al. (2017)

DEFF Research Database (Denmark)

McGlone, Matt S.; Buitenwerf, Robert; Richardson, Sarah J.

2017-01-01

Grubb et al. (2017) point out that we (McGlone et al. 2016) erroneously stated that the definition of warm temperate rain forest (WTRF; Grubb et al. 2013) was based in part on climatic criteria. We apologise: their text made clear that this was not the case. However, they go on to say that they ‘...

Constructed Rain Garden Systems for Stormwater Quality Control under Tropical Climates

Science.gov (United States)

Mohd Sidek, Lariyah; Elyza Muha, Norshafa; Noor, Nur Asmaliza Md; Basri, Hidayah

2013-06-01

Malaysia has taken an integrated approach to manage storm water that is increasingly becoming a problem in big cities. Rain gardens are recommended as green technology for a new storm water management in Malaysia. The approach is applied in urban planning and design that integrates the total water cycle management into the development process areas. Rain gardens have been effective in reducing peak discharge and consistently reduce the number of storm water pollutants. This paper will examine some of guidelines, laboratory studies and field monitoring that shows great potential and benefit of rain garden. The preliminary results for rain garden performance were reported in this paper. The findings from this research will open avenues for researchers to advance the knowledge in rain garden systems to achieve the sustainable development in Malaysia.

Constructed Rain Garden Systems for Stormwater Quality Control under Tropical Climates

International Nuclear Information System (INIS)

Sidek, Lariyah Mohd; Noor, Nur Asmaliza Md; Basri, Hidayah; Muha, Norshafa Elyza

2013-01-01

Malaysia has taken an integrated approach to manage storm water that is increasingly becoming a problem in big cities. Rain gardens are recommended as green technology for a new storm water management in Malaysia. The approach is applied in urban planning and design that integrates the total water cycle management into the development process areas. Rain gardens have been effective in reducing peak discharge and consistently reduce the number of storm water pollutants. This paper will examine some of guidelines, laboratory studies and field monitoring that shows great potential and benefit of rain garden. The preliminary results for rain garden performance were reported in this paper. The findings from this research will open avenues for researchers to advance the knowledge in rain garden systems to achieve the sustainable development in Malaysia.

What do computer worlds tell us about changes to rain and falling ice-water in the state where this meeting is usually held?

Science.gov (United States)

Langenbrunner, B.

2017-12-01

To learn how the world will change because of human-caused warming, we use computer-made worlds that couple land, water, and air to study their responses to the causes of warming over many years. For changes to rain and falling ice-water, these computer worlds are great at answering questions about very large places, like big areas of land or water, but they are not as good when thinking about more focused areas, like cities or states. This is especially true in the state where this meeting happens most years; will it be wetter or drier by the year 2100, and by how much? I will talk about the work being done to learn why these computer worlds do not always agree, as well as the work that finds changes on which they do agree. One big reason they don't agree is because these computer worlds arrive at different guesses on how winds will shift high up in the air in cooler months. These winds will push rain and falling ice-water to different places up and down the state over time, making it hard to know what we can expect, though our best guess is that it will be ever-so-slightly wetter. Computer worlds do agree, however, on two important things across most of the state: that the very largest bursts of rain will happen more often as the world warms, and that more often, very wet years will follow very dry years immediately before them. Taken together, these changes are important to the those in the state who plan for up-coming water needs. Knowing how normal rain and ice-water will change is part of the story, but perhaps more important is understanding how the very biggest showers are shifting, which will help the state plan for and handle these more sudden (and serious) bursts of water.

Utilization of genetic variation created through induced mutations to develop drought tolerant groundnut mutants for the sandy rain-fed areas of western Sudan

International Nuclear Information System (INIS)

Abdalla, E. G. A.

2000-10-01

Groundnut (Arachis hypogaea. L.) is grown as a cash crop throughout the tropical and warm temperate regions of the world. Approximately 80% of the global production comes from developing countries and 67% of the total is produced in the seasonally rain fed areas of the semi-arid tropics (Gibbons, 1980). In Sudan, groundnut is grown under rain fed and irrigated sectors. Rain fed production accounts for 80% of the total production. Yield under the traditional rain fed farming conditions are very low (700kg/ha) compared to the world average (1200kg/ha). Low rainfall (250-450 mm) and short growing seasons (<90 days) are major constraints to groundnut production. Under these situations survival of the subsistence farmers depends entirely on minimizing the probabilities of crop failure. This can to some extent be addressed by adopting short term strategies of incorporating various physiological defense mechanisms into crop varieties to allow a certain level of realized yield in a more reliable manner (Subbarao et al, 1995)

Survival probability of precipitations and rain attenuation in tropical and equatorial regions

Science.gov (United States)

Mohebbi Nia, Masoud; Din, Jafri; Panagopoulos, Athanasios D.; Lam, Hong Yin

2015-08-01

This contribution presents a stochastic model useful for the generation of a long-term tropospheric rain attenuation time series for Earth space or a terrestrial radio link in tropical and equatorial heavy rain regions based on the well-known Cox-Ingersoll-Ross model previously employed in research in the fields of finance and economics. This model assumes typical gamma distribution for rain attenuation in heavy rain climatic regions and utilises the temporal dynamic of precipitation collected in equatorial Johor, Malaysia. Different formations of survival probability are also discussed. Furthermore, the correlation between these probabilities and the Markov process is determined, and information on the variance and autocorrelation function of rain events with respect to the particular characteristics of precipitation in this area is presented. The proposed technique proved to preserve the peculiarities of precipitation for an equatorial region and reproduce fairly good statistics of the rain attenuation correlation function that could help to improve the prediction of dynamic characteristics of rain fade events.

[Analysis of acid rain characteristics of Lin'an Regional Background Station using long-term observation data].

Science.gov (United States)

Li, Zheng-Quan; Ma, Hao; Mao, Yu-Ding; Feng, Tao

2014-02-01

Using long-term observation data of acid rain at Lin'an Regional Background Station (Lin'an RBS), this paper studied the interannual and monthly variations of acid rain, the reasons for the variations, and the relationships between acid rain and meteorological factors. The results showed that interannual variation of acid rain at Lin'an RBS had a general increasing trend in which there were two obvious intensifying processes and two distinct weakening processes, during the period ranging from 1985 to 2012. In last two decades, the monthly variation of acid rain at Lin'an RBS indicated that rain acidity and frequency of severe acid rain were increasing but the frequency of weak acid rain was decreasing when moving towards bilateral side months of July. Acid rain occurrence was affected by rainfall intensity, wind speed and wind direction. High frequency of severe acid rain and low frequency of weak acid rain were on days with drizzle, but high frequency of weak acid rain and low frequency of severe acid rain occurred on rainstorm days. With wind speed upgrading, the frequency of acid rain and the proportion of severe acid rain were declining, the pH value of precipitation was reducing too. Another character is that daily dominant wind direction of weak acid rain majorly converged in S-W section ,however that of severe acid rain was more likely distributed in N-E section. The monthly variation of acid rain at Lin'an RBS was mainly attributed to precipitation variation, the increasing and decreasing of monthly incoming wind from SSE-WSW and NWN-ENE sections of wind direction. The interannual variation of acid rain could be due to the effects of energy consumption raising and significant green policies conducted in Zhejiang, Jiangsu and Shanghai.

Spontaneuos and Parametric Processes in Warm Rubidium Vapours

Directory of Open Access Journals (Sweden)

Dąbrowski M.

2014-12-01

Full Text Available Warm rubidium vapours are known to be a versatile medium for a variety of experiments in atomic physics and quantum optics. Here we present experimental results on producing the frequency converted light for quantum applications based on spontaneous and stimulated processes in rubidium vapours. In particular, we study the efficiency of spontaneously initiated stimulated Raman scattering in the Λ-level configuration and conditions of generating the coherent blue light assisted by multi-photon transitions in the diamond-level configuration. Our results will be helpful in search for new types of interfaces between light and atomic quantum memories.

Particle transport patterns of short-distance soil erosion by wind-driven rain, rain and wind

Science.gov (United States)

Marzen, Miriam; Iserloh, Thomas; de Lima, João L. M. P.; Ries, Johannes B.

2015-04-01

Short distance erosion of soil surface material is one of the big question marks in soil erosion studies. The exact measurement of short-distance transported soil particles, prior to the occurrence of overland flow, is a challenge to soil erosion science due to the particular requirements of the experimental setup and test procedure. To approach a quantification of amount and distance of each type of transport, we applied an especially developed multiple-gutter system installed inside the Trier Portable Wind and Rainfall Simulator (PWRS). We measured the amount and travel distance of soil particles detached and transported by raindrops (splash), wind-driven rain (splash-saltation and splash-drift) and wind (saltation). The test setup included three different erosion agents (rain/ wind-driven rain/ wind), two substrates (sandy/ loamy), three surface structures (grain roughness/ rills lengthwise/ rills transversal) and three slope angles (0°/+7°/-7°). The results present detailed transport patterns of the three erosion agents under the varying soil and surface conditions up to a distance of 1.6 m. Under the applied rain intensity and wind velocity, wind-driven rain splash generates the highest erosion. The erodibility and travel distance of the two substrates depend on the erosion agent. The total erosion is slightly higher for the slope angle -7° (downslope), but for wind-driven rain splash, the inclination is not a relevant factor. The effect of surface structures (rills) changes with traveling distance. The wind driven rain splash generates a much higher amount of erosion and a further travel distance of the particles due to the combined action of wind and rain. The wind-driven rain factor appears to be much more significant than the other factors. The study highlights the effects of different erosion agents and surface parameters on short-distance particle transport and the powerful impact of wind-driven rain on soil erosion.

Exploring the Relationship between Prior Knowledge on Rain Gardens and Supports for Adopting Rain Gardens Using a Structural Equation Model

Directory of Open Access Journals (Sweden)

Suyeon Kim

2018-05-01

Full Text Available The objective of this study was to determine the effect of prior knowledge and visual evaluation on supports for rain garden installations. To achieve this objective, a survey was conducted to obtain prior knowledge of rain gardens, rain garden implementation support ratings, and visual evaluation of rain gardens in 100 visitors of three rain garden sites. Results of the analysis revealed that users’ visual evaluation of rain gardens played a role as a moderator in the relationship between prior knowledge and support for rain garden installations. In other words, education and publicity of rain gardens alone cannot increase support for rain gardens. However, if rain gardens are visually evaluated positively, the effects of education and publicity of rain gardens can be expected. Therefore, to successfully apply a rain garden policy in the future, basic consideration should be given to aesthetics in order to meet visitors’ visual expectations prior to education and publicity of rain gardens.

Rain Forest Murals

Science.gov (United States)

Kleiner, Cheryl

2010-01-01

The rain forest murals in the author's school began as a request from her principal to have students decorate the cafeteria with their own paintings. She decided to brainstorm ideas with her eighth-grade students. Taking into consideration the architectural space and the environmental concerns they wanted to convey, students chose the rain forest…

Assessment of global expected warming contribution to desertification process development in Kazakhstan

International Nuclear Information System (INIS)

Dolgih, S.A.; Eserkepova, I.B.; Shamen, A.M.

1997-01-01

Assessment of moistening condition change in Kazakhstan and its role in processes of desertification at global expected climate warming are cited. Results of numerical experiments by models of common circulation of atmosphere have been used in capacity of potential regional climate change characteristics. (author)

Climate change consequences for terrestrial ecosystem processes in NW Greeland: Results from the High Arctic Biocomplexity project

Science.gov (United States)

Welker, J. M.; Sullivan, P.; Rogers, M.; Sharp, E. D.; Sletten, R.; Burnham, J. L.; Hallet, B.; Hagedorn, B.; Czimiczk, C.

2009-12-01

Greenland is experiencing some of the fastest rates of climate warming across the Arctic including warmer summers and increases in snow fall. The effects of these new states of Greenland are however, uncertain especially for carbon, nitrogen and water biogeochemical processes, soil traits, vegetation growth patterns, mineral nutrition and plant ecophysiological processes. Since 2003 we have conducted a suite of observational and experimental measurements that have been designed to understand the fundamental nature of polar desert, polar semi-desert and fen landscapes in NW Greenland. In addition, we have established a suite of experiments to ascertain ecosystem responses to warming at multiple levels (~2030 and 2050), in conjunction with added summer rain; the consequences of added snow fall (ambient, intermediate and deep) and the effects of increases in nutrient additions (added N, P and N+P), which represent extreme warming conditions. We find that: a) the soil C pools are 6-fold larger than previously measured, b) extremely old C (up to ~30k bp) which has been buried by frost cracking and frost heaving is reaching the modern atmosphere, but in only trace amounts as measured by respired 14CO2, c) warming that simulates 2030, has only a small effect on net C sequestration but warming that simulates 2050 when combined with added summer rain, increases C sequestration by 300%, d) increases in N deposition almost immediately and completely changes the vegetation composition of polar semi-deserts shifting the NDVI values from 0.2 to 0.5 within 2 years. Our findings depict a system that is poised to contribute stronger feedbacks than previously expected as climates in NW Greenland change.

Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming

International Nuclear Information System (INIS)

Oreskes, Naomi; Conway, Erik M.; Treiner, Jacques

2012-01-01

The U.S. scientific community has long led the world in research on public health, environmental science, and other issues affecting the quality of life. US scientists have produced landmark studies on the dangers of DDT, tobacco smoke, acid rain, and global warming. But at the same time, a small yet potent subset of this community leads the world in vehement denial of these dangers. In this book, the historian authors explain how a loose-knit group of high-level scientists, with extensive political connections, ran effective campaigns to mislead the public and deny well-established scientific knowledge over four decades. In seven compelling chapters addressing tobacco, acid rain, the ozone hole, global warming, and DDT, they roll back the rug on this dark corner of the American scientific community, showing how the ideology of free market fundamentalism, aided by a too-compliant media, has skewed public understanding of some of the most pressing issues of our era

The 183-WSL Fast Rain Rate Retrieval Algorithm. Part II: Validation Using Ground Radar Measurements

Science.gov (United States)

Laviola, Sante; Levizzani, Vincenzo

2014-01-01

performs better during the warm months, while during the winter time the discrepancies with radar measurements tends to maximum values. A stable behavior of the 183-WSL algorithm is demonstrated over the whole study period with an overall overestimation for rain rates intensities lower than 1 millimeter per hour. This threshold is crucial especially in wintertime where the low precipitation regime is difficult to be classified.

Possible impacts of climate change on freezing rain in south-central Canada using downscaled future climate scenarios

Directory of Open Access Journals (Sweden)

C. S. Cheng

2007-01-01

Full Text Available Freezing rain is a major atmospheric hazard in mid-latitude nations of the globe. Among all Canadian hydrometeorological hazards, freezing rain is associated with the highest damage costs per event. Using synoptic weather typing to identify the occurrence of freezing rain events, this study estimates changes in future freezing rain events under future climate scenarios for south-central Canada. Synoptic weather typing consists of principal components analysis, an average linkage clustering procedure (i.e., a hierarchical agglomerative cluster method, and discriminant function analysis (a nonhierarchical method. Meteorological data used in the analysis included hourly surface observations from 15 selected weather stations and six atmospheric levels of six-hourly National Centers for Environmental Prediction (NCEP upper-air reanalysis weather variables for the winter months (November–April of 1958/59–2000/01. A statistical downscaling method was used to downscale four general circulation model (GCM scenarios to the selected weather stations. Using downscaled scenarios, discriminant function analysis was used to project the occurrence of future weather types. The within-type frequency of future freezing rain events is assumed to be directly proportional to the change in frequency of future freezing rain-related weather types The results showed that with warming temperatures in a future climate, percentage increases in the occurrence of freezing rain events in the north of the study area are likely to be greater than those in the south. By the 2050s, freezing rain events for the three colder months (December–February could increase by about 85% (95% confidence interval – CI: ±13%, 60% (95% CI: ±9%, and 40% (95% CI: ±6% in northern Ontario, eastern Ontario (including Montreal, Quebec, and southern Ontario, respectively. The increase by the 2080s could be even greater: about 135% (95% CI: ±20%, 95% (95% CI: ±13%, and 45% (95% CI: ±9

Evaluation of the RAIN project

International Nuclear Information System (INIS)

Stuanes, A.; Dickson, W.; Jenkins, A.; Rasmussen, L.; Stordal, F.

1991-11-01

This report presents a scientific assessment of the RAIN project. It describes the main hypotheses tested and the applied methods. The major results of the research are highlighted and discussed, and they are placed in the perspective of national and international acid rain research. An important part of the RAIN project has been to provide information to the public about the acid rain problem, and in this way it has performed an important background role in influencing political decisions and legislation. The RAIN project is regarded as a cost effective research effort, and the novel approach and capital investment will enable further manipulation studies at these sites in the future. It is recommended that the project is continued in the immediate future, with some modification to answer specific questions resulting from the collected data. 24 refs., 6 figs., 1 tab

analysis of rain analysis of rain rate and rain attenuation for earth

African Journals Online (AJOL)

eobe

rate measurements were carried out using the Moupfouma and Chebil models ate measurements were ... The rain in Nigeria is characterized by high intensity rainfall, high frequency of ..... Journal of Atmospheric and Solar-. Terrestrial Physics ...

Rain scavenging of radioactive particles

International Nuclear Information System (INIS)

Williams, A.L.

1975-01-01

An assessment is made of the rainout of airborne radioactive particles from a nuclear detonation with emphasis on the microphysical removal processes. For submicron particles the scavenging processes examined are Brownian and turbulent diffusion to cloud droplets. For particles larger than 1 μm radius, nucleation scavenging is examined. For various particle size and radioactivity distributions, it is found that from 27 to 99 percent of the radioactivity is attached to cloud droplets and subject to rapid removal by rain. (U.S.)

Politics of environmental regulation: acid rain in Ontario

Energy Technology Data Exchange (ETDEWEB)

Hogarth Wood, G P

1984-01-01

This study looks at the case of the Ontario government and Inco Limited in order to explain political responses to the acid rain issue and to generalize about the dynamics of environmental regulation. Existing accounts of the acid rain situation neglect a systematic explanation of the political processes that guide the selection of policy. This reflects a tendency in Canadian public policy analysis generally. Most literature in this field is both apolitical and atheoretical. In addition, most models of public policy focus attention on a narrow range of policy determinants, making the models inappropriate as exclusive guides for public policy analysis. This study follows an approach that assumes that no variable can, a priori, be viewed as the primary determinant of a policy choice. Instead, relevant features of the economic, social, and political environment surrounding the policy process have to be examined in addition to that process itself. Accordingly, a number of potential influences on the acid rain policy outcome in Ontario are explored: the economic structure of Ontario, political-geographic factors, the role of science and technology, political power in the province, political values and attitudes, the institutional structure of Ontario politics, and finally, the policy process itself. This exercise points to the overriding influence of the political system environment, particularly the economic structure of the province, in explaining the policy choice. The findings of this study can be extended to explain regulatory responses to the issue in other political jurisdictions.

Rain effect on Aquarius L-band Emissivity and Backscatter Model Functions

Science.gov (United States)

Tang, W.; Yueh, S. H.; Fore, A.; Neumann, G.; Hayashi, A.

2012-12-01

Remote sensing of sea surface salinity (SSS) is being performed by Aquarius and SMOS missions, which are using L-band radiometry to sense the microwave emissions from sea surfaces. To enable accurate SSS retrieval, it is essential to correct the impact of sea surface roughness on L-band brightness temperatures. In addition, the impact of rain has to be carefully assessed and accounted for. Although the atmospheric attenuation caused by raindrops are likely negligible at 1.4GHz, other factors must be considered because they may have indirect but important contribution to the surface roughness and consequently L-band brightness temperatures. For example, the wind speed dependent roughness correction will be corrupted when rain striking the water, creating rings, stalks, and crowns from which the signal scatters. It is also unknown how long the freshwater stays at surface while through the oceanic mixing process at various regions over global oceans. We collocated the Aquarius L-band data with various wind products, including SSM/I, NCEP, ASCAT and WindSAT, as well as the SSM/I and WindSAT rain products. During the first four months of Aquarius mission, near 1.9 million pixels are identified under rain conditions by either SSM/I or WindSAT. We derived the L-band emissivity and backscatter geophysical model functions (GMF), parameterized by SSM/I and NCEP winds for rain-free conditions. However, the residual ocean surface emissivity (the Aquarius measured minus the rain-free model predictions) reveals profound resemblance with global precipitation pattern. In region dominated by rain, e.g. ITCZ, northern hemisphere storm track, and Indian Ocean partially under the influence of summer monsoon, the GMF built using rain free data underestimates excess emissivity about 0.5 to 1 K. The dependence of residual of emissivity and backscatter is shown as a function of wind speed and rain rate. A modified GMF is developed including rain rate as one of the parameters. Due to

Spread of acid rain over India

Science.gov (United States)

Khemani, L. T.; Momin, G. A.; Rao, P. S. Prakasa; Safai, P. D.; Singh, G.; Kapoor, R. K.

Rain water and aerosol samples were collected at a few locations representative of urban and non-urban regions in India. Also, rain water samples were collected in and around a coal-fired power plant. All the rain water and aerosol samples were analyzed for major chemical components along with pH. The rain water at all the places of measurement, except near the industrial sources, has been found to be alkaline and was characterized by the presence of excess cations, particularly by Ca 2+. The acid rain near the industrial sources was associated with excess anions, especially SO 42-. The atmospheric aerosols at all the places of measurement were found rich with basic components, suggesting that the alkaline soil dust and fly ash are responsible at present for preventing the spread of acid rain in India.

When It Rains, It Pours

Science.gov (United States)

Mills, Linda

2012-01-01

"It's raining, it's pouring, the old man is snoring!" "The itsy, bitsy spider crawled up the waterspout, down came the rain and washed the spider out. Out came the sun and dried up all the rain, and the itsy, bitsy spider went up the spout again." What do children's nursery rhymes have to do with the school library? The author begins by telling a…

Data driven analysis of rain events: feature extraction, clustering, microphysical /macro physical relationship

Science.gov (United States)

Djallel Dilmi, Mohamed; Mallet, Cécile; Barthes, Laurent; Chazottes, Aymeric

2017-04-01

The study of rain time series records is mainly carried out using rainfall rate or rain accumulation parameters estimated on a fixed integration time (typically 1 min, 1 hour or 1 day). In this study we used the concept of rain event. In fact, the discrete and intermittent natures of rain processes make the definition of some features inadequate when defined on a fixed duration. Long integration times (hour, day) lead to mix rainy and clear air periods in the same sample. Small integration time (seconds, minutes) will lead to noisy data with a great sensibility to detector characteristics. The analysis on the whole rain event instead of individual short duration samples of a fixed duration allows to clarify relationships between features, in particular between macro physical and microphysical ones. This approach allows suppressing the intra-event variability partly due to measurement uncertainties and allows focusing on physical processes. An algorithm based on Genetic Algorithm (GA) and Self Organising Maps (SOM) is developed to obtain a parsimonious characterisation of rain events using a minimal set of variables. The use of self-organizing map (SOM) is justified by the fact that it allows to map a high dimensional data space in a two-dimensional space while preserving as much as possible the initial space topology in an unsupervised way. The obtained SOM allows providing the dependencies between variables and consequently removing redundant variables leading to a minimal subset of only five features (the event duration, the rain rate peak, the rain event depth, the event rain rate standard deviation and the absolute rain rate variation of order 0.5). To confirm relevance of the five selected features the corresponding SOM is analyzed. This analysis shows clearly the existence of relationships between features. It also shows the independence of the inter-event time (IETp) feature or the weak dependence of the Dry percentage in event (Dd%e) feature. This confirms

Acid rain information book. Final report

International Nuclear Information System (INIS)

1983-05-01

Acid rain is one of the most widely publicized environmental issues of the day. The potential consequences of widespread acid rain demand that the phenomenon be carefully evaluated. Review of the literature shows a rapidly growing body of knowledge, but also reveals major gaps in understanding that need to be narrowed. This document discusses aspects of the acid rain phenomenon, points out areas of uncertainty and summarizes current and projected research. The report is organized by a logical progression from sources of pollutants affecting acid rain formation to the atmospheric transport and transformation of those pollutants and finally to the deposition of acid rain, the effects of that deposition, and possible mitigative measures and regulatory options. This information is followed by a discussion of uncertainties in the understanding of the acid rain phenomenon and a description of current and proposed research by responsible government agencies and other concerned organizations

Contrasting effects of summer and winter warming on body mass explain population dynamics in a food-limited Arctic herbivore.

Science.gov (United States)

Albon, Steve D; Irvine, R Justin; Halvorsen, Odd; Langvatn, Rolf; Loe, Leif E; Ropstad, Erik; Veiberg, Vebjørn; van der Wal, René; Bjørkvoll, Eirin M; Duff, Elizabeth I; Hansen, Brage B; Lee, Aline M; Tveraa, Torkild; Stien, Audun

2017-04-01

The cumulative effects of climate warming on herbivore vital rates and population dynamics are hard to predict, given that the expected effects differ between seasons. In the Arctic, warmer summers enhance plant growth which should lead to heavier and more fertile individuals in the autumn. Conversely, warm spells in winter with rainfall (rain-on-snow) can cause 'icing', restricting access to forage, resulting in starvation, lower survival and fecundity. As body condition is a 'barometer' of energy demands relative to energy intake, we explored the causes and consequences of variation in body mass of wild female Svalbard reindeer (Rangifer tarandus platyrhynchus) from 1994 to 2015, a period of marked climate warming. Late winter (April) body mass explained 88% of the between-year variation in population growth rate, because it strongly influenced reproductive loss, and hence subsequent fecundity (92%), as well as survival (94%) and recruitment (93%). Autumn (October) body mass affected ovulation rates but did not affect fecundity. April body mass showed no long-term trend (coefficient of variation, CV = 8.8%) and was higher following warm autumn (October) weather, reflecting delays in winter onset, but most strongly, and negatively, related to 'rain-on-snow' events. October body mass (CV = 2.5%) increased over the study due to higher plant productivity in the increasingly warm summers. Density-dependent mass change suggested competition for resources in both winter and summer but was less pronounced in recent years, despite an increasing population size. While continued climate warming is expected to increase the carrying capacity of the high Arctic tundra, it is also likely to cause more frequent icing events. Our analyses suggest that these contrasting effects may cause larger seasonal fluctuations in body mass and vital rates. Overall our findings provide an important 'missing' mechanistic link in the current understanding of the population biology of a

Grain refinement and mechanical properties of CP-Ti processed by warm accumulative roll bonding

International Nuclear Information System (INIS)

Milner, Justin L.; Abu-Farha, Fadi; Bunget, Cristina; Kurfess, Thomas; Hammond, Vincent H.

2013-01-01

Accumulative roll bonding (ARB), a severe plastic deformation technique, was used in this study to process commercially pure titanium (CP-Ti) at 450 °C. Sheet samples were processed by seven consecutive ARB cycles, with an overall equivalent strain of 5.6. Mechanical characterization and microstructural examination were carried out on the processed material to track their changes and relationships with regard to one another. Electron microscopy, TEM in particular, revealed significant grain refinement in the material, with submicron microstructure achieved even after one cycle of warm processing. Further processing was shown to progressively fragment the highly elongated grains, ultimately producing a predominantly-equiaxed ultrafine grain structure with an average grain size of ∼100 nm. Tensile strength and microhardness of the material increased with the number of ARB cycles; the strength–grain size relationship followed the Hall–Petch equation. The overall grain refinement and strengthening levels observed here are close to those reported in the literature for ARB processing of CP-Ti at ambient temperatures. This demonstrates the ability of warm ARB can be as effective as cold ARB, while offering several advantages for industrial utilization.

Coastal and rain-induced wind variability depicted by scatterometers

Science.gov (United States)

Portabella, M.; Lin, W.; Stoffelen, A.; Turiel, A.; Verhoef, A.; Verspeek, J.; Ballabrera, J.; Vogelzang, J.

2012-04-01

A detailed knowledge of local wind variability near the shore is very important since it strongly affects the weather and microclimate in coastal regions. Since coastal areas are densely populated and most activity at sea occurs near the shore, sea-surface wind field information is important for a number of applications. In the vicinity of land sea-breeze, wave fetch, katabatic and current effects are more likely than in the open ocean, thus enhancing air-sea interaction. Also very relevant for air-sea interaction are the rain-induced phenomena, such as downbursts and convergence. Relatively cold and dry air is effectively transported to the ocean surface and surface winds are enhanced. In general, both coastal and rain-induced wind variability are poorly resolved by Numerical Weather Prediction (NWP) models. Satellite real aperture radars (i.e., scatterometers) are known to provide accurate mesoscale (25-50 km resolution) sea surface wind field information used in a wide variety of applications. Nowadays, there are two operating scatterometers in orbit, i.e., the C-band Advanced Scatterometer (ASCAT) onboard Metop-A and the Ku-band scatterometer (OSCAT) onboard Oceansat-2. The EUMETSAT Ocean and Sea Ice Satellite Application Facility (OSI SAF) delivers several ASCAT level 2 wind products with 25 km and 12.5 km Wind Vector Cell (WVC) spacing, including a pre-operational coastal wind product as well as an OSCAT level 2 wind product with 50 km spacing in development status. Rain is known to both attenuate and scatter the microwave signal. In addition, there is a "splashing" effect. The roughness of the sea surface is increased because of splashing due to rain drops. The so-called "rain contamination" is larger for Ku-band scatterometer systems than for C-band systems. Moreover, the associated downdrafts lead to variable wind speeds and directions, further complicating the wind retrieval. The C-band ASCAT high resolution wind processing is validated under rainy

A statistical rain attenuation prediction model with application to the advanced communication technology satellite project. Part 2: Theoretical development of a dynamic model and application to rain fade durations and tolerable control delays for fade countermeasures

Science.gov (United States)

Manning, Robert M.

1987-01-01

A dynamic rain attenuation prediction model is developed for use in obtaining the temporal characteristics, on time scales of minutes or hours, of satellite communication link availability. Analagous to the associated static rain attenuation model, which yields yearly attenuation predictions, this dynamic model is applicable at any location in the world that is characterized by the static rain attenuation statistics peculiar to the geometry of the satellite link and the rain statistics of the location. Such statistics are calculated by employing the formalism of Part I of this report. In fact, the dynamic model presented here is an extension of the static model and reduces to the static model in the appropriate limit. By assuming that rain attenuation is dynamically described by a first-order stochastic differential equation in time and that this random attenuation process is a Markov process, an expression for the associated transition probability is obtained by solving the related forward Kolmogorov equation. This transition probability is then used to obtain such temporal rain attenuation statistics as attenuation durations and allowable attenuation margins versus control system delay.

Rainfall timing and runoff: The influence of the criterion for rain event separation

OpenAIRE

Molina-Sanchis, Isabel; Lázaro, Roberto; Arnau-Rosalén, Eva; Calvo-Cases, Adolfo

2016-01-01

Rain is not uniform in time and space in semiarid areas and its distribution is very important for the runoff process. Hydrological studies usually divide rainfall into events. However, defining rain events is complicated, and rain characteristics vary depending on how the events are delimited. Choosing a minimum inter-event time (MIT) is a commonly used criterion. Our hypothesis is that there will be an optimal MIT that explains the maximum part of the variance of the runoff, with time to ru...

Weighing Rain Gauge Recording Charts

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Weighing rain gauge charts record the amount of precipitation that falls at a given location. The vast majority of the Weighing Rain Gauge Recording Charts...

Acid rain attack on outdoor sculpture in perspective

Science.gov (United States)

Livingston, Richard A.

2016-12-01

A major concern motivating research in acid rain materials effects has been the potential for damage to cultural heritage, particularly outdoor marble and bronze sculpture. However, a combination of field and laboratory studies has failed to show a correlation between rain pH and loss of materials. In order to understand this counterintuitive lack of acid rain effect, an aqueous geochemical modeling approach was used to analyze rain runoff chemistry for the relative importance of acid rain neutralization, dry deposition, and in the case of marble, natural carbonate dissolution. This approach involved the development of pH - SO42- phase diagrams for marble (calcium carbonate) and bronze (copper) under ambient environmental conditions. This then enabled reaction path modeling of the acid neutralization process using the pH range typically found in wet deposition (3.5-6). The results were for marble that the theoretical maximum amount of Ca2+ ion that could be lost due acid rain neutralization would be 0.158 mmol/l compared to 10.5 mmol/l by dry deposition, and for bronze, the Cu2+ ion losses would be 0.21 mmol/l and 47.3 mmol/l respectively. Consequently dry deposition effects on these materials have the potential to dominate over wet deposition effects. To test these predictions the geochemical models were applied to examples of data sets from mass balance (runoff vs rainfall) studies on a marble statue in New York City and some bronze memorial plaques at Gettysburg PA. Although these data sets were collected in the early 1980s they remain valid for demonstrating the mass balance method. For the marble statue, the mean Ca2+ losses by dry deposition was about 69% of the total compared 0.3% for acid rain neutralization, which was less than the natural carbonate dissolution losses of 0.8%. For the bronze, the mean Cu2+ losses were 70.6% by SO42- dry deposition and 23% by NO3- dry deposition compared to 6.4% by acid rain neutralization. Thus for both cases the wet

Competition between core and periphery-based processes in warm convective clouds – from invigoration to suppression

OpenAIRE

G. Dagan; I. Koren; O. Altaratz

2015-01-01

How do changes in the amount and properties of aerosol affect warm clouds? Recent studies suggest that they have opposing effects. Some suggest that an increase in aerosol loading leads to enhanced evaporation and therefore smaller clouds, whereas other studies suggest clouds' invigoration. In this study, using an axisymmetric bin-microphysics cloud model, we propose a theoretical scheme that analyzes the evolution of key processes in warm clouds, under different aerosol loa...

Recharge the Rain: Community Resilience Through STEM Education

Science.gov (United States)

Wilkening, B.; Shipek, C.

2017-12-01

Starting in January 2017, Recharge the Rain moves sixth through twelfth grade teachers, students and the public through a continuum from awareness, to knowledge gain, to conceptual understanding, to action; building community resiliency to hazards associated with increased temperatures, drought and flooding in Arizona. Watershed Management Group with Arizona Project WET are utilizing NOAA assets, experts from the National Weather Service and Climate Assessment for the Southwest (CLIMAS), and Pima County hazard mitigation plan and planning tools to inform citizens and galvanize their commitment to building a community, resilient to the effects of a warming climate. In the first of four years, the project is 1) developing climate-literacy curriculum with 16 Tucson-area teachers that incorporates systems-thinking and increases understanding of earth systems, weather and climate, 2) training teachers and community docents in water harvesting practices and citizen-science data collection, 3) laying the framework for the development of rainwater harvesting engineering design curriculum, 4) involving Tucson community members in water harvesting principles through project implementation workshops, special events, and tours. In years two through four, the project will build resiliency to the effects of climate threats by 1) installing student-designed rainwater harvesting systems, 2) providing community tours of schoolyard systems to educate the public, 3) expanding the program to incorporate curriculum use in Phoenix-area teachers' classrooms and 4) finalizing a replicable model for other communities facing similar threats. What are the lessons learned after one year of Recharge the Rain? How can these lessons be used to inform this project and other projects in building resilient communities?

Simulated Acid Rain-induced Alterations in Flowering, Leaf ...

African Journals Online (AJOL)

ADOWIE PERE

significantly in test plant with decreasing pH of acid rain solution. Acid rain application ... indicates the sunflower plant turns to be an acid rain sensitive system and demands for breeding with acid rain ..... Changes in growth, pigmentation and ...

Ethical choices and global climate warming

Energy Technology Data Exchange (ETDEWEB)

Dotto, L

1994-01-01

The ethical implications of global warming are discussed, and a summary is presented of a study on ethics and climate change. Deciding the 'best' approaches depends on point of view, whether this be of a Canadian, a Somali, great grandchildren, the Amazon rain forest or a kangaroo. The spectrum of possible actions runs from avoidance to adaptation. Avoidance focuses on strategies to reduce the greenhouse effect by curtailing greenhouse gas emissions or preventing these emissions from reaching the atmosphere. Adaptation strategies help to cope with the negative consequences of allowing emissions to continue. Philosophers and ethicists have expressed a wide range of opinions on the consequences, responsibilities, limitations, and legal mechanisms involved in determining global warming action. A profound shift in corporate thinking is called for, with less emphasis on short-term bottom line. The role of governments and other institutions is debated, and questions are raised about the economic strategies that will best protect the interests of future generations. Energy efficiency and conservation must be reflected in the economic equation. Public cynicism with regard to political leaders is such that they are unlikely to credited with any degree of ethical motivation, a view that may be unwarranted. Ethical principles must become more central in the formulation of policies.

Warm measurements of CBA superconducting magnets

International Nuclear Information System (INIS)

Engelmann, R.; Herrera, J.; Kahn, S.; Kirk, H.; Willen, E.; Yamin, P.

1983-01-01

We present results on magnetic field measurements of CBA dipole magnets in the warm (normal conductor) and cryogenic (superconducting) states. We apply two methods for the warm measurements, a dc and ac method. We find a good correlation between warm and cryogenic measurements which lends itself to a reliable diagnosis of magnet field errors using warm measurements early in the magnet assembly process. We further find good agreement between the two warm measurement methods, both done at low currents

Rain Gardens: Stormwater Infiltrating Systems

Science.gov (United States)

The hydrological dynamics and changes in stormwater nutrient concentrations within rain gardens were studied by introducing captured stormwater runoff to rain gardens at EPA’s Urban Water Research Facility in Edison, New Jersey. The runoff used in these experiments was collected...

Large projected increases in rain-on-snow flood potential over western North America

Science.gov (United States)

Musselman, K. N.; Ikeda, K.; Barlage, M. J.; Lehner, F.; Liu, C.; Newman, A. J.; Prein, A. F.; Mizukami, N.; Gutmann, E. D.; Clark, M. P.; Rasmussen, R.

2017-12-01

In the western US and Canada, some of the largest annual flood events occur when warm storm systems drop substantial rainfall on extensive snow-cover. For example, last winter's Oroville dam crisis in California was exacerbated by rapid snowmelt during a rain-on-snow (ROS) event. We present an analysis of ROS events with flood-generating potential over western North America simulated at high-resolution by the Weather Research and Forecasting (WRF) model run for both a 13-year control time period and re-run with a `business-as-usual' future (2071-2100) climate scenario. Daily ROS with flood-generating potential is defined as rainfall of at least 10 mm per day falling on snowpack of at least 10 mm water equivalent, where the sum of rainfall and snowmelt contains at least 20% snowmelt. In a warmer climate, ROS is less frequent in regions where it is historically common, and more frequent elsewhere. This is evidenced by large simulated reductions in snow-cover and ROS frequency at lower elevations, particularly in warmer, coastal regions, and greater ROS frequency at middle elevations and in inland regions. The same trend is reflected in the annual-average ROS runoff volume (rainfall + snowmelt) aggregated to major watersheds; large reductions of 25-75% are projected for much of the U.S. Pacific Northwest, while large increases are simulated for the Colorado River basin, western Canada, and the higher elevations of the Sierra Nevada. In the warmer climate, snowmelt contributes substantially less to ROS runoff per unit rainfall, particularly in inland regions. The reduction in snowmelt contribution is due to a shift in ROS timing from warm spring events to cooler winter conditions and/or from warm, lower elevations to cool, higher elevations. However, the slower snowmelt is offset by an increase in rainfall intensity, maintaining the flood potential of ROS at or above historical levels. In fact, we report large projected increases in the intensity of extreme ROS events

Whither Acid Rain?

Directory of Open Access Journals (Sweden)

Peter Brimblecombe

2000-01-01

Full Text Available Acid rain, the environmental cause célèbre of the 1980s seems to have vanished from popular conscience. By contrast, scientific research, despite funding difficulties, has continued to produce hundreds of research papers each year. Studies of acid rain taught much about precipitation chemistry, the behaviour of snow packs, long-range transport of pollutants and new issues in the biology of fish and forested ecosystems. There is now evidence of a shift away from research in precipitation and sulfur chemistry, but an impressive theoretical base remains as a legacy.

Rain pulse response of soil CO2 exchange by biological soil crusts and grasslands of the semiarid Colorado Plateau, United States

Science.gov (United States)

Bowling, David R.; Grote, E.E.; Belnap, J.

2011-01-01

Biological activity in arid grasslands is strongly dependent on moisture. We examined gas exchange of biological soil crusts (biocrusts), the underlying soil biotic community, and the belowground respiratory activity of C3 and C4 grasses over 2 years in southeast Utah, USA. We used soil surface CO2 flux and the amount and carbon isotope composition (δ13C) of soil CO2 as indicators of belowground and soil surface activity. Soil respiration was always below 2 μmol m-2s-1 and highly responsive to soil moisture. When moisture was available, warm spring and summer temperature was associated with higher fluxes. Moisture pulses led to enhanced soil respiration lasting for a week or more. Biological response to rain was not simply dependent on the amount of rain, but also depended on antecedent conditions (prior moisture pulses). The short-term temperature sensitivity of respiration was very dynamic, showing enhancement within 1-2 days of rain, and diminishing each day afterward. Carbon uptake occurred by cyanobacterially dominated biocrusts following moisture pulses in fall and winter, with a maximal net carbon uptake of 0.5 μmol m-2s-1, although typically the biocrusts were a net carbon source. No difference was detected in the seasonal activity of C3 and C4 grasses, contrasting with studies from other arid regions (where warm- versus cool-season activity is important), and highlighting the unique biophysical environment of this cold desert. Contrary to other studies, the δ13C of belowground respiration in the rooting zone of each photosynthetic type did not reflect the δ13C of C3 and C4 physiology.

Intra-event isotope and raindrop size data of tropical rain reveal effects concealed by event averaged data

Science.gov (United States)

Managave, S. R.; Jani, R. A.; Narayana Rao, T.; Sunilkumar, K.; Satheeshkumar, S.; Ramesh, R.

2016-08-01

Evaporation of rain is known to contribute water vapor, a potent greenhouse gas, to the atmosphere. Stable oxygen and hydrogen isotopic compositions (δ18O and, δD, respectively) of precipitation, usually measured/presented as values integrated over rain events or monthly mean values, are important tools for detecting evaporation effects. The slope ~8 of the linear relationship between such time-averaged values of δD and δ18O (called the meteoric water line) is widely accepted as a proof of condensation under isotopic equilibrium and absence of evaporation of rain during atmospheric fall. Here, through a simultaneous investigation of the isotopic and drop size distributions of seventeen rain events sampled on an intra-event scale at Gadanki (13.5°N, 79.2°E), southern India, we demonstrate that the evaporation effects, not evident in the time-averaged data, are significantly manifested in the sub-samples of individual rain events. We detect this through (1) slopes significantly less than 8 for the δD-δ18O relation on intra-event scale and (2) significant positive correlations between deuterium excess ( d-excess = δD - 8*δ18O; lower values in rain indicate evaporation) and the mass-weighted mean diameter of the raindrops ( D m ). An estimated ~44 % of rain is influenced by evaporation. This study also reveals a signature of isotopic equilibration of rain with the cloud base vapor, the processes important for modeling isotopic composition of precipitation. d-excess values of rain are modified by the post-condensation processes and the present approach offers a way to identify the d-excess values least affected by such processes. Isotope-enabled global circulation models could be improved by incorporating intra-event isotopic data and raindrop size dependent isotopic effects.

Design and performance of combined infrared canopy and belowground warming in the B4WarmED (Boreal Forest Warming at an Ecotone in Danger) experiment.

Science.gov (United States)

Rich, Roy L; Stefanski, Artur; Montgomery, Rebecca A; Hobbie, Sarah E; Kimball, Bruce A; Reich, Peter B

2015-06-01

Conducting manipulative climate change experiments in complex vegetation is challenging, given considerable temporal and spatial heterogeneity. One specific challenge involves warming of both plants and soils to depth. We describe the design and performance of an open-air warming experiment called Boreal Forest Warming at an Ecotone in Danger (B4WarmED) that addresses the potential for projected climate warming to alter tree function, species composition, and ecosystem processes at the boreal-temperate ecotone. The experiment includes two forested sites in northern Minnesota, USA, with plots in both open (recently clear-cut) and closed canopy habitats, where seedlings of 11 tree species were planted into native ground vegetation. Treatments include three target levels of plant canopy and soil warming (ambient, +1.7°C, +3.4°C). Warming was achieved by independent feedback control of voltage input to aboveground infrared heaters and belowground buried resistance heating cables in each of 72-7.0 m(2) plots. The treatments emulated patterns of observed diurnal, seasonal, and annual temperatures but with superimposed warming. For the 2009 to 2011 field seasons, we achieved temperature elevations near our targets with growing season overall mean differences (∆Tbelow ) of +1.84°C and +3.66°C at 10 cm soil depth and (∆T(above) ) of +1.82°C and +3.45°C for the plant canopies. We also achieved measured soil warming to at least 1 m depth. Aboveground treatment stability and control were better during nighttime than daytime and in closed vs. open canopy sites in part due to calmer conditions. Heating efficacy in open canopy areas was reduced with increasing canopy complexity and size. Results of this study suggest the warming approach is scalable: it should work well in small-statured vegetation such as grasslands, desert, agricultural crops, and tree saplings (<5 m tall). © 2015 John Wiley & Sons Ltd.

A new mechanism for warm-season precipitation response to global warming based on convection-permitting simulations

Science.gov (United States)

Dai, Aiguo; Rasmussen, Roy M.; Liu, Changhai; Ikeda, Kyoko; Prein, Andreas F.

2017-08-01

Climate models project increasing precipitation intensity but decreasing frequency as greenhouse gases increase. However, the exact mechanism for the frequency decrease remains unclear. Here we investigate this by analyzing hourly data from regional climate change simulations with 4 km grid spacing covering most of North America using the Weather Research and Forecasting model. The model was forced with present and future boundary conditions, with the latter being derived by adding the CMIP5 19-model ensemble mean changes to the ERA-interim reanalysis. The model reproduces well the observed seasonal and spatial variations in precipitation frequency and histograms, and the dry interval between rain events over the contiguous US. Results show that overall precipitation frequency indeed decreases during the warm season mainly due to fewer light-moderate precipitation (0.1 2.0 mm/h) events, while heavy (2 10 mm/h) events increase. Dry spells become longer and more frequent, together with a reduction in time-mean relative humidity (RH) in the lower troposphere during the warm season. The increased dry hours and decreased RH lead to a reduction in overall precipitation frequency and also for light-moderate precipitation events, while water vapor-induced increases in precipitation intensity and the positive latent heating feedback in intense storms may be responsible for the large increase in intense precipitation. The size of intense storms increases while their number decreases in the future climate, which helps explain the increase in local frequency of heavy precipitation. The results generally support a new hypothesis for future warm-season precipitation: each rainstorm removes ≥7% more moisture from the air per 1 K local warming, and surface evaporation and moisture advection take slightly longer than currently to replenish the depleted moisture before the next storm forms, leading to longer dry spells and a reduction in precipitation frequency, as well as

Rain Simulation for the Test of Automotive Surround Sensors

Science.gov (United States)

Hasirlioglu, Sinan; Riener, Andreas; Doric, Igor

2017-04-01

The WHO Global Health Observatory data indicates that over 1.25 million people die in traffic accidents annually. To save lives, car manufacturers spend lot of efforts on the development of novel safety systems aiming to avoid or mitigate accidents and provide maximum protection for vehicle occupants as well as vulnerable road users. All the safety features mainly rely on data from surround sensors such as radar, lidar and camera and intelligent vehicles today use these environmental data for instant decision making and vehicle control. As already small errors in sensor data measurements could lead to catastrophes like major injuries or road traffic fatalities, it is of utmost importance to ensure high reliability and accuracy of sensors and safety systems. This work focuses on the influence of environmental factors such as rain conditions, as it is known that rain drops scatter the electromagnetic waves. The result is incorrect measurements with a direct negative impact on environment detection. To identify potential problems of sensors under varying environmental conditions, systems are today tested in real-world settings with two main problems: First, tests are time-consuming and second, environmental conditions are not reproducible. Our approach to test the influence of weather on automotive sensors is to use an indoor rain simulator. Our artificial rain maker, installed at CARISSMA (Center of Automotive Research on Integrated Safety Systems and Measurement Area), is parametrized with rain characteristics measured in the field using a standard disdrometer. System behavior on artificial rain is compared and validated with natural rainfall. With this simulator it is finally possible to test environmental influence at various levels and under reproducible conditions. This saves lot of efforts required for the test process itself and furthermore has a positive impact on the reliability of sensor systems due to the fact that test driven development is enabled.

Acid Rain: An Educational Opportunity?

Science.gov (United States)

Marion, James I.

1984-01-01

Deals with how educators can handle the subject of acid rain; illustrates suggestions with experiences of grade nine students visiting Frost Valley Environmental Education Center (Oliverea, New York) to learn scientific concepts through observation of outdoor phenomena, including a stream; and discusses acid rain, pH levels, and pollution control…

MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

Energy Technology Data Exchange (ETDEWEB)

Fang, X.; Xia, C.; Keppens, R. [Centre for mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, B-3001 Leuven (Belgium)

2013-07-10

We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

International Nuclear Information System (INIS)

Fang, X.; Xia, C.; Keppens, R.

2013-01-01

We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

Response of soil respiration to acid rain in forests of different maturity in southern China.

Directory of Open Access Journals (Sweden)

Guohua Liang

Full Text Available The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF, a transitional mixed conifer and broadleaf forest (MF and an old-growth broadleaved forest (BF] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0. Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

Response of soil respiration to acid rain in forests of different maturity in southern China.

Science.gov (United States)

Liang, Guohua; Liu, Xingzhao; Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

2013-01-01

The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

The Impact of Aerosols on Cloud and Precipitation Processes: Cloud-Resolving Model Simulations

Science.gov (United States)

Tao, Wei-Kuo; Li, Xiaowen; Khain, Alexander; Matsui, Toshihisa; Lang, Stephen; Simpson, Joanne

2008-01-01

Aerosols and especially their effect on clouds are one of the key components of the climate system and the hydrological cycle [Ramanathan et al., 2001]. Yet, the aerosol effect on clouds remains largely unknown and the processes involved not well understood. A recent report published by the National Academy of Science states "The greatest uncertainty about the aerosol climate forcing - indeed, the largest of all the uncertainties about global climate forcing - is probably the indirect effect of aerosols on clouds [NRC, 2001]." The aerosol effect on clouds is often categorized into the traditional "first indirect (i.e., Twomey)" effect on the cloud droplet sizes for a constant liquid water path [Twomey, 1977] and the "semi-direct" effect on cloud coverage [e.g., Ackerman et al ., 2001]." Enhanced aerosol concentrations can also suppress warm rain processes by producing a narrow droplet spectrum that inhibits collision and coalescence processes [e.g., Squires and Twomey, 1961; Warner and Twomey, 1967; Warner, 1968; Rosenfeld, 19991. The aerosol effect on precipitation processes, also known as the second type of aerosol indirect effect [Albrecht, 1989], is even more complex, especially for mixed-phase convective clouds. Table 1 summarizes the key observational studies identifying the microphysical properties, cloud characteristics, thermodynamics and dynamics associated with cloud systems from high-aerosol continental environments. For example, atmospheric aerosol concentrations can influence cloud droplet size distributions, warm-rain process, cold-rain process, cloud-top height, the depth of the mixed phase region, and occurrence of lightning. In addition, high aerosol concentrations in urban environments could affect precipitation variability by providing an enhanced source of cloud condensation nuclei (CCN). Hypotheses have been developed to explain the effect of urban regions on convection and precipitation [van den Heever and Cotton, 2007 and Shepherd, 2005

Observation and Estimation of Evapotranspiration from an Irrigated Green Roof in a Rain-Scarce Environment

Directory of Open Access Journals (Sweden)

Youcan Feng

2018-03-01

Full Text Available While the rain-driven evapotranspiration (ET process has been well-studied in the humid climate, the mixed irrigation and rain-driven ET process is less understood for green roof implementations in dry regions, where empirical observations and model parameterizations are lacking. This paper presents an effort of monitoring and simulating the ET process for an irrigated green roof in a rain-scarce environment. Annual ET rates for three weighing lysimeter test units with non-vegetated, sedums, and grass covers were 2.01, 2.52, and 2.69 mm d−1, respectively. Simulations based on the three Penman–Monteith equation-derived models achieved accuracy within the reported range of previous studies. Compared to the humid climate, the overestimation of high ET rates by existing models is expected to cause a larger error in dry environments, where the enhanced ET process caused by repeated irrigations overlapped with hot, dry conditions often occurs during summer. The studied sedum species did not show significantly lower ET rates than native species, and could not effectively take advantage of the deep moisture storage. Therefore, native species, instead of the shallow-rooted species commonly recommended in humid climates, might be a better choice for green roofs in rain-scarce environments.

The influence of global warming on natural disasters and their public health outcomes.

Science.gov (United States)

Diaz, James H

2007-01-01

With a documented increase in average global surface temperatures of 0.6 degrees C since 1975, Earth now appears to be warming due to a variety of climatic effects, most notably the cascading effects of greenhouse gas emissions resulting from human activities. There remains, however, no universal agreement on how rapidly, regionally, or asymmetrically the planet will warm or on the true impact of global warming on natural disasters and public health outcomes. Most reports to date of the public health impact of global warming have been anecdotal and retrospective in design and have focused on the increase in heat-stroke deaths following heat waves and on outbreaks of airborne and arthropod-borne diseases following tropical rains and flooding that resulted from fluctuations in ocean temperatures. The effects of global warming on rainfall and drought, tropical cyclone and tsunami activity, and tectonic and volcanic activity will have far-reaching public health effects not only on environmentally associated disease outbreaks but also on global food supplies and population movements. As a result of these and other recognized associations between climate change and public health consequences, many of which have been confounded by deficiencies in public health infrastructure and scientific debates over whether climate changes are spawned by atmospheric cycles or anthropogenic influences, the active responses to progressive climate change must include combinations of economic, environmental, legal, regulatory, and, most importantly, public health measures.

RAIN

DEFF Research Database (Denmark)

Monti, Matteo; Rasmussen, Steen

2017-01-01

We summarize the results and perspectives from a companion article, where we presented and evaluated an alternative architecture for data storage in distributed networks. We name the bio-inspired architecture RAIN, and it offers file storage service that, in contrast with current centralized clou...... will integrate multiple current and future infrastructures ranging from online services and cryptocurrency to parts of government administration....

Deep Joint Rain Detection and Removal from a Single Image

OpenAIRE

Yang, Wenhan; Tan, Robby T.; Feng, Jiashi; Liu, Jiaying; Guo, Zongming; Yan, Shuicheng

2016-01-01

In this paper, we address a rain removal problem from a single image, even in the presence of heavy rain and rain streak accumulation. Our core ideas lie in the new rain image models and a novel deep learning architecture. We first modify an existing model comprising a rain streak layer and a background layer, by adding a binary map that locates rain streak regions. Second, we create a new model consisting of a component representing rain streak accumulation (where individual streaks cannot b...

Use of the RAINS model in acid rain negotiations in Europe

International Nuclear Information System (INIS)

Hordijk, L.

1991-01-01

The use of models in international negotiations on environmental problems for which no compulsory action can be imposed is a recent trend. In the past, international agreements have been reached without any model being used. For example, the first step in reducing acid rain in Europe and North America was made in 1985 without using an integrated model. Neither was a model used to establish the Vienna Convention on Protection of the Ozone Layer (1986). Analyzing the reasons for using mathematical models in environmental negotiations is not the subject of this paper. Suffice it to say there are several recent examples of models being used in preparing international policy actions, for instance the Law of the Sea and the Intergovernmental Panel on Climate Change. The acceptance of models as tools in negotiations depends on many factors. The differences in the attitudes toward use of models in the case of assessment of acid rain in Europe and North America have been analyzed. In this paper, the author reviews the current use of the RAINS model and points out some lessons for the development of models that could be used in international environmental negotiations

Wind scatterometry with improved ambiguity selection and rain modeling

Science.gov (United States)

Draper, David Willis

Although generally accurate, the quality of SeaWinds on QuikSCAT scatterometer ocean vector winds is compromised by certain natural phenomena and retrieval algorithm limitations. This dissertation addresses three main contributors to scatterometer estimate error: poor ambiguity selection, estimate uncertainty at low wind speeds, and rain corruption. A quality assurance (QA) analysis performed on SeaWinds data suggests that about 5% of SeaWinds data contain ambiguity selection errors and that scatterometer estimation error is correlated with low wind speeds and rain events. Ambiguity selection errors are partly due to the "nudging" step (initialization from outside data). A sophisticated new non-nudging ambiguity selection approach produces generally more consistent wind than the nudging method in moderate wind conditions. The non-nudging method selects 93% of the same ambiguities as the nudged data, validating both techniques, and indicating that ambiguity selection can be accomplished without nudging. Variability at low wind speeds is analyzed using tower-mounted scatterometer data. According to theory, below a threshold wind speed, the wind fails to generate the surface roughness necessary for wind measurement. A simple analysis suggests the existence of the threshold in much of the tower-mounted scatterometer data. However, the backscatter does not "go to zero" beneath the threshold in an uncontrolled environment as theory suggests, but rather has a mean drop and higher variability below the threshold. Rain is the largest weather-related contributor to scatterometer error, affecting approximately 4% to 10% of SeaWinds data. A simple model formed via comparison of co-located TRMM PR and SeaWinds measurements characterizes the average effect of rain on SeaWinds backscatter. The model is generally accurate to within 3 dB over the tropics. The rain/wind backscatter model is used to simultaneously retrieve wind and rain from SeaWinds measurements. The simultaneous

Acid rain stimulation of Lake Michigan phytoplankton growth

Science.gov (United States)

Manny, Bruce A.; Fahnenstiel, G.L.; Gardner, W.S.

1987-01-01

Three laboratory experiments demonstrated that additions of rainwater to epilimnetic lake water collected in southeastern Lake Michigan stimulated chlorophyll a production more than did additions of reagent-grade water during incubations of 12 to 20 d. Chlorophyll a production did not begin until 3–5 d after the rain and lake water were mixed. The stimulation caused by additions of rain acidified to pH 3.0 was greater than that caused by additions of untreated rain (pH 4.0–4.5). Our results support the following hypotheses: (1) Acid rain stimulates the growth of phytoplankton in lake water; (2) phosphorus in rain appears to be the factor causing this stimulation. We conclude that acid rain may accelerate the growth of epilimnetic phytoplankton in Lake Michigan (and other similar lakes) during stratification when other sources of bioavailable phosphorus to the epilimnion are limited

Differences in rain rate intensities between TRMM observations and community atmosphere model simulations

Science.gov (United States)

Deng, Yi; Bowman, Kenneth P.; Jackson, Charles

2007-01-01

Precipitation related latent heating is important in driving the atmospheric general circulation and in generating intraseasonal to decadal atmospheric variability. Our ability to project future climate change, especially trends in costly precipitation extremes, hinges upon whether coupled GCMs capture processes that affect precipitation characteristics. Our study compares the tropical-subtropical precipitation characteristics of simulations by the NCAR CAM3.1 atmospheric GCM and observations derived from the NASA Tropical Rainfall Measuring Mission (TRMM) satellite. Despite a fairly good simulation of the annual mean rain rate, CAM rains about 10-50% more often than the real world and fails to capture heavy rainfall associated with deep convective systems over subtropical South America and U.S. Southern Plains. When it rains, there is a likelihood of 0.96-1.0 that it rains lightly in the model, compared to values of 0.84-1.0 in TRMM data. On the other hand, the likelihood of the occurrence of moderate to heavy rainfall is an order of magnitude higher in observations (0.12-0.2) than that in the model (model compensates for the lack of heavy precipitation through raining more frequently within the light rain category, which leads to an annual rainfall amount close to what is observed. CAM captures the qualitative change of rain rate PDF from a "dry" oceanic to a "wet" oceanic region, but it fails to simulate the change of precipitation characteristics from an oceanic region to a land region where thunderstorm rainfall dominates.

Coronal rain in magnetic bipolar weak fields

Science.gov (United States)

Xia, C.; Keppens, R.; Fang, X.

2017-07-01

Aims: We intend to investigate the underlying physics for the coronal rain phenomenon in a representative bipolar magnetic field, including the formation and the dynamics of coronal rain blobs. Methods: With the MPI-AMRVAC code, we performed three dimensional radiative magnetohydrodynamic (MHD) simulation with strong heating localized on footpoints of magnetic loops after a relaxation to quiet solar atmosphere. Results: Progressive cooling and in-situ condensation starts at the loop top due to radiative thermal instability. The first large-scale condensation on the loop top suffers Rayleigh-Taylor instability and becomes fragmented into smaller blobs. The blobs fall vertically dragging magnetic loops until they reach low-β regions and start to fall along the loops from loop top to loop footpoints. A statistic study of the coronal rain blobs finds that small blobs with masses of less than 1010 g dominate the population. When blobs fall to lower regions along the magnetic loops, they are stretched and develop a non-uniform velocity pattern with an anti-parallel shearing pattern seen to develop along the central axis of the blobs. Synthetic images of simulated coronal rain with Solar Dynamics Observatory Atmospheric Imaging Assembly well resemble real observations presenting dark falling clumps in hot channels and bright rain blobs in a cool channel. We also find density inhomogeneities during a coronal rain "shower", which reflects the observed multi-stranded nature of coronal rain. Movies associated to Figs. 3 and 7 are available at http://www.aanda.org

quantification of rain quantification of rain induced artifacts on digital

African Journals Online (AJOL)

eobe

DSTV) ... satellite television, rain attenuation, digital artifacts, pixelation, rainfall rate. 1. ... screen and blocking are commonly observed in .... The precipitation data was collected using a self- ..... Networks: Comparison at Equatorial and Subtropical.

Influence of acid rain and organic matter on the adsorption of trace elements on soil

International Nuclear Information System (INIS)

Wang, H.; Ambe, S.; Takematsu, N.; Ambe, F.

1998-01-01

Acid rain has become one of the most serious environmental problems. Soil loses its buffering capacity by long exposure to acid rain, and the soil pH value decreases significantly. The acidification of the soil disturbs the adsorption equilibrium of many elements in the soil-water system. Soil is a very complex heterogeneous system, primarily consisting of clay minerals, hydrous oxides and polymeric organic substances, which possess their own characteristic element-adsorbing properties. On the other hand, the intrinsic properties of elements are reflected in their adsorption process as a matter of course. Therefore, both the effects of the pH of acid rain and that of the components of the soil on the adsorption of different elements should be studied when the adsorption process in acid soils is to be clarified. Although leaching of major cations in soil, such as Ca 2+ , Mg 2+ and Al 3+ , by acid rain, has been extensively studied, relatively little attention has been focused on trace elements which can also seriously affect the ecological system. We studied the acid rain effects on element adsorption by kaolin, forest soil, black soil, and also these soils with Fe- and Mn-oxides or organic matter selectively removed by using the radioactive multitracer technique. (author)

Rain-on-snow and ice layer formation detection using passive microwave radiometry: An arctic perspective

Science.gov (United States)

Langlois, A.; Royer, A.; Montpetit, B.; Johnson, C. A.; Brucker, L.; Dolant, C.; Richards, A.; Roy, A.

2015-12-01

With the current changes observed in the Arctic, an increase in occurrence of rain-on-snow (ROS) events has been reported in the Arctic (land) over the past few decades. Several studies have established that strong linkages between surface temperatures and passive microwaves do exist, but the contribution of snow properties under winter extreme events such as rain-on-snow events (ROS) and associated ice layer formation need to be better understood that both have a significant impact on ecosystem processes. In particular, ice layer formation is known to affect the survival of ungulates by blocking their access to food. Given the current pronounced warming in northern regions, more frequent ROS can be expected. However, one of the main challenges in the study of ROS in northern regions is the lack of meteorological information and in-situ measurements. The retrieval of ROS occurrence in the Arctic using satellite remote sensing tools thus represents the most viable approach. Here, we present here results from 1) ROS occurrence formation in the Peary caribou habitat using an empirically developed ROS algorithm by our group based on the gradient ratio, 2) ice layer formation across the same area using a semi-empirical detection approach based on the polarization ratio spanning between 1978 and 2013. A detection threshold was adjusted given the platform used (SMMR, SSM/I and AMSR-E), and initial results suggest high-occurrence years as: 1981-1982, 1992-1993; 1994-1995; 1999-2000; 2001-2002; 2002-2003; 2003-2004; 2006-2007; 2007-2008. A trend in occurrence for Banks Island and NW Victoria Island and linkages to caribou population is presented.

Pyrite oxidation under simulated acid rain weathering conditions.

Science.gov (United States)

Zheng, Kai; Li, Heping; Wang, Luying; Wen, Xiaoying; Liu, Qingyou

2017-09-01

We investigated the electrochemical corrosion behavior of pyrite in simulated acid rain with different acidities and at different temperatures. The cyclic voltammetry, polarization curve, and electrochemical impedance spectroscopy results showed that pyrite has the same electrochemical interaction mechanism under different simulated acid rain conditions, regardless of acidity or environmental temperature. Either stronger acid rain acidity or higher environmental temperature can accelerate pyrite corrosion. Compared with acid rain having a pH of 5.6 at 25 °C, the prompt efficiency of pyrite weathering reached 104.29% as the acid rain pH decreased to 3.6, and it reached 125.31% as environmental temperature increased to 45 °C. Increasing acidity dramatically decreases the charge transfer resistance, and increasing temperature dramatically decreases the passivation film resistance, when other conditions are held constant. Acid rain always causes lower acidity mine drainage, and stronger acidity or high environmental temperatures cause serious acid drainage. The natural parameters of latitude, elevation, and season have considerable influence on pyrite weathering, because temperature is an important influencing factor. These experimental results are of direct significance for the assessment and management of sulfide mineral acid drainage in regions receiving acid rain.

The Effect of Rain on Air-Water Gas Exchange

Science.gov (United States)

Ho, David T.; Bliven, Larry F.; Wanninkhof, Rik; Schlosser, Peter

1997-01-01

The relationship between gas transfer velocity and rain rate was investigated at NASA's Rain-Sea Interaction Facility (RSIF) using several SF, evasion experiments. During each experiment, a water tank below the rain simulator was supersaturated with SF6, a synthetic gas, and the gas transfer velocities were calculated from the measured decrease in SF6 concentration with time. The results from experiments with IS different rain rates (7 to 10 mm/h) and 1 of 2 drop sizes (2.8 or 4.2 mm diameter) confirm a significant and systematic enhancement of air-water gas exchange by rainfall. The gas transfer velocities derived from our experiment were related to the kinetic energy flux calculated from the rain rate and drop size. The relationship obtained for mono-dropsize rain at the RSIF was extrapolated to natural rain using the kinetic energy flux of natural rain calculated from the Marshall-Palmer raindrop size distribution. Results of laboratory experiments at RSIF were compared to field observations made during a tropical rainstorm in Miami, Florida and show good agreement between laboratory and field data.

Chemical characteristics of rain-water

International Nuclear Information System (INIS)

Kasahara, Mikio; Ogiwara, Hiroshi; Park, Jeong-Ho; Takahashi, Kanji

1994-01-01

Rain drops were collected every 0.1mm precipitation. Rain water was passed through a Nuclepore filter with 0.2μm pore-size. Chemical species in the filtrate and the residue are defined as a soluble and an insoluble component, respectively. Dry PIXE samples from filtrate were prepared bydropping and evaporating successively ten 20μ l drops with a micropipet onto a non-hole thin film. The drops were dried in a spot-like of 4mmφ such that all of the samples were bombarded by 6mmφ ion beam. Elemental concentrations were determined with 2.0 MeV H + beam from a Tandem accelerator. X-rays with 0.5-14.8keV energy were detected by a Si(Li) detector after passing through a 39.3μm thick Maylar absorber. The concentrations of all analyzed 15 elements in both insoluble and soluble components decreased rapidly from the beginning of rain to the amount of 0.3mm rain fall as well asban electrical conductivity. Most of Si and Fe were insoluble, on the other hand, most of S and Cl were soluble. (author)

Resource Aware Intelligent Network Services (RAINS) Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Lehman, Tom; Yang, Xi

2018-01-16

The Resource Aware Intelligent Network Services (RAINS) project conducted research and developed technologies in the area of cyberinfrastructure resource modeling and computation. The goal of this work was to provide a foundation to enable intelligent, software defined services which spanned the network AND the resources which connect to the network. A Multi-Resource Service Plane (MRSP) was defined, which allows resource owners/managers to locate and place themselves from a topology and service availability perspective within the dynamic networked cyberinfrastructure ecosystem. The MRSP enables the presentation of integrated topology views and computation results which can include resources across the spectrum of compute, storage, and networks. The RAINS project developed MSRP includes the following key components: i) Multi-Resource Service (MRS) Ontology/Multi-Resource Markup Language (MRML), ii) Resource Computation Engine (RCE), iii) Modular Driver Framework (to allow integration of a variety of external resources). The MRS/MRML is a general and extensible modeling framework that allows for resource owners to model, or describe, a wide variety of resource types. All resources are described using three categories of elements: Resources, Services, and Relationships between the elements. This modeling framework defines a common method for the transformation of cyberinfrastructure resources into data in the form of MRML models. In order to realize this infrastructure datification, the RAINS project developed a model based computation system, i.e. “RAINS Computation Engine (RCE)”. The RCE has the ability to ingest, process, integrate, and compute based on automatically generated MRML models. The RCE interacts with the resources thru system drivers which are specific to the type of external network or resource controller. The RAINS project developed a modular and pluggable driver system which facilities a variety of resource controllers to automatically generate

Rain-induced spring wheat harvest losses

Science.gov (United States)

Bauer, A.; Black, A. L. (Principal Investigator)

1983-01-01

When rain or a combination of rain and high humidity delay wheat harvest, losses can occur in grain yield and/or grain quality. Yield losses can result from shattering, from reduction in test weight, and in the case of windrowed grain, from rooting of sprouting grain at the soil: windrow contact. Losses in grain quality can result from reduction in test weight and from sprouting. Sprouting causes a degradation of grain proteins and starches, hence flour quality is reduced, and the grain price deteriorates to the value of feed grain. Although losses in grain yield and quality are rain-induced, these losses do not necessarily occur because a standing or windrowed crop is wetted by rain. Spike water concentration in hard red spring wheat must be increased to about 45-49% before sprouting is initiated in grain that has overcome dormancy. The time required to overcome this dormancy after the cultivar has dried to 12 to 14% water concentration differs with hard red spring cultivars. The effect of rain on threshing-ready standing and windrowed hard red spring wheat grain yeild and quality was evaluated. A goal was to develop the capability to forecast the extent of expected loss of grain yield and quality from specific climatic events that delay threshing.

Rain garden guidelines for southwest Ohio

Science.gov (United States)

Rain gardens are a unique and practical landscape feature that can enhance the beauty of home gardens. When properly installed, they are one method of limiting the negative effects of rainfall runoff in urban areas. Indeed, rain gardens turn a "negative" into a "positive" by capt...

Evidence of late Palaeocene-early Eocene equatorial rain forest refugia in southern Western Ghats, India.

Science.gov (United States)

Prasad, V; Farooqui, A; Tripathi, S K M; Garg, R; Thakur, B

2009-11-01

Equatorial rain forests that maintain a balance between speciation and extinction are hot-spots for studies of biodiversity. Western Ghats in southern India have gained attention due to high tropical biodiversity and endemism in their southern most area. We attempted to track the affinities of the pollen fl ora of the endemic plants of Western Ghat area within the fossil palynoflora of late Palaeocene-early Eocene (approximately 55-50 Ma) sedimentary deposits of western and northeastern Indian region. The study shows striking similarity of extant pollen with twenty eight most common fossil pollen taxa of the early Palaeogene. Widespread occurrences of coal and lignite deposits during early Palaeogene provide evidence of existence of well diversified rain forest community and swampy vegetation in the coastal low lying areas all along the western and northeastern margins of the Indian subcontinent. Prevalence of excessive humid climate during this period has been seen as a result of equatorial positioning of Indian subcontinent, superimposed by a long term global warming phase (PETM and EECO) during the early Palaeogene. The study presents clear evidence that highly diversifi ed equatorial rain forest vegetation once widespread in the Indian subcontinent during early Palaeogene times, are now restricted in a small area as a refugia in the southernmost part of the Western Ghat area. High precipitation and shorter periods of dry months seem to have provided suitable environment to sustain lineages of ancient tropical vegetation in this area of Western Ghats in spite of dramatic climatic changes subsequent to the post India-Asia collision and during the Quaternary and Recent times.

Experimental warming decreases arbuscular mycorrhizal fungal colonization in prairie plants along a Mediterranean climate gradient

Directory of Open Access Journals (Sweden)

Hannah Wilson

2016-06-01

Full Text Available Background: Arbuscular mycorrhizal fungi (AMF provide numerous services to their plant symbionts. Understanding climate change effects on AMF, and the resulting plant responses, is crucial for predicting ecosystem responses at regional and global scales. We investigated how the effects of climate change on AMF-plant symbioses are mediated by soil water availability, soil nutrient availability, and vegetation dynamics. Methods: We used a combination of a greenhouse experiment and a manipulative climate change experiment embedded within a Mediterranean climate gradient in the Pacific Northwest, USA to examine this question. Structural equation modeling (SEM was used to determine the direct and indirect effects of experimental warming on AMF colonization. Results: Warming directly decreased AMF colonization across plant species and across the climate gradient of the study region. Other positive and negative indirect effects of warming, mediated by soil water availability, soil nutrient availability, and vegetation dynamics, canceled each other out. Discussion: A warming-induced decrease in AMF colonization would likely have substantial consequences for plant communities and ecosystem function. Moreover, predicted increases in more intense droughts and heavier rains for this region could shift the balance among indirect causal pathways, and either exacerbate or mitigate the negative, direct effect of increased temperature on AMF colonization.

Feedback attribution of the land-sea warming contrast in a global warming simulation of the NCAR CCSM4

International Nuclear Information System (INIS)

Sejas, Sergio A; Albert, Oriene S; Cai, Ming; Deng, Yi

2014-01-01

One of the salient features in both observations and climate simulations is a stronger land warming than sea. This paper provides a quantitative understanding of the main processes that contribute to the land-sea warming asymmetry in a global warming simulation of the NCAR CCSM4. The CO 2 forcing alone warms the surface nearly the same for both land and sea, suggesting that feedbacks are responsible for the warming contrast. Our analysis on one hand confirms that the principal contributor to the above-unity land-to-sea warming ratio is the evaporation feedback; on the other hand the results indicate that the sensible heat flux feedback has the largest land-sea warming difference that favors a greater ocean than land warming. Therefore, the results uniquely highlight the importance of other feedbacks in establishing the above-unity land-to-sea warming ratio. Particularly, the SW cloud feedback and the ocean heat storage in the transient response are key contributors to the greater warming over land than sea. (letter)

Response of plasma membrane H+-ATPase in rice (Oryza sativa) seedlings to simulated acid rain.

Science.gov (United States)

Liang, Chanjuan; Ge, Yuqing; Su, Lei; Bu, Jinjin

2015-01-01

Understanding the adaptation of plants to acid rain is important to find feasible approaches to alleviate such damage to plants. We studied effects of acid rain on plasma membrane H(+)-ATPase activity and transcription, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate during stress and recovery periods. Simulated acid rain at pH 5.5 did not affect plasma membrane H(+)-ATPase activity, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate. Plasma membrane H(+)-ATPase activity and transcription in leaves treated with acid rain at pH 3.5 was increased to maintain ion homeostasis by transporting excessive H(+) out of cells. Then intracellular H(+) was close to the control after a 5-day recovery, alleviating damage on membrane and sustaining photosynthetic efficiency and growth. Simulated acid rain at pH 2.5 inhibited plasma membrane H(+)-ATPase activity by decreasing the expression of H(+)-ATPase at transcription level, resulting in membrane damage and abnormal intracellular H(+), and reduction in photosynthetic efficiency and relative growth rate. After a 5-day recovery, all parameters in leaves treated with pH 2.5 acid rain show alleviated damage, implying that the increased plasma membrane H(+)-ATPase activity and its high expression were involved in repairing process in acid rain-stressed plants. Our study suggests that plasma membrane H(+)-ATPase can play a role in adaptation to acid rain for rice seedlings.

A westward extension of the tropical Pacific warm pool leads to March through June drying in Kenya and Ethiopia

Science.gov (United States)

Williams, A. Park; Funk, Christopher C.

2010-01-01

An estimated 14.3 million people are currently (July 2010) food insecure in Kenya and Ethiopia, and the U.S. government has spent more than $972 million on food aid in these two countries since 2009 (USAID, 2010). This insecurity stems from recent drought and rapid population growth that has outpaced agricultural development (Funk and others, 2008; Funk and Brown, 2009). Previous work by Funk and others (2005, 2008) and Verdin and others (2005) has linked drought conditions in Kenya and Ethiopia with warm sea surface temperatures (SSTs) in the Indian Ocean. Recent work has shown that Indian Ocean SSTs substantially affect rainfall in this region from March through June (Funk and others, 2008; Funk and Verdin, 2009). This season is known as the 'long rains' in Kenya and the 'Belg' rains in Ethiopia.

Acid rain information book. Draft final report

Energy Technology Data Exchange (ETDEWEB)

None

1980-12-01

Acid rain is one of the most widely publicized environmental issues of the day. The potential consequences of increasingly widespread acid rain demand that this phenomenon be carefully evaluated. Reveiw of the literature shows a rapidly growing body of knowledge, but also reveals major gaps in understanding that need to be narrowed. This document discusses major aspects of the acid rain phenomenon, points out areas of uncertainty, and summarizes current and projected research by responsible government agencies and other concerned organizations.

Rain events decrease boreal peatland net CO2 uptake through reduced light availability.

Science.gov (United States)

Nijp, Jelmer J; Limpens, Juul; Metselaar, Klaas; Peichl, Matthias; Nilsson, Mats B; van der Zee, Sjoerd E A T M; Berendse, Frank

2015-06-01

Boreal peatlands store large amounts of carbon, reflecting their important role in the global carbon cycle. The short-term exchange and the long-term storage of atmospheric carbon dioxide (CO2 ) in these ecosystems are closely associated with the permanently wet surface conditions and are susceptible to drought. Especially, the single most important peat forming plant genus, Sphagnum, depends heavily on surface wetness for its primary production. Changes in rainfall patterns are expected to affect surface wetness, but how this transient rewetting affects net ecosystem exchange of CO2 (NEE) remains unknown. This study explores how the timing and characteristics of rain events during photosynthetic active periods, that is daytime, affect peatland NEE and whether rain event associated changes in environmental conditions modify this response (e.g. water table, radiation, vapour pressure deficit, temperature). We analysed an 11-year time series of half-hourly eddy covariance and meteorological measurements from Degerö Stormyr, a boreal peatland in northern Sweden. Our results show that daytime rain events systematically decreased the sink strength of peatlands for atmospheric CO2 . The decrease was best explained by rain associated reduction in light, rather than by rain characteristics or drought length. An average daytime growing season rain event reduced net ecosystem CO2 uptake by 0.23-0.54 gC m(-2) . On an annual basis, this reduction of net CO2 uptake corresponds to 24% of the annual net CO2 uptake (NEE) of the study site, equivalent to a 4.4% reduction of gross primary production (GPP) during the growing season. We conclude that reduced light availability associated with rain events is more important in explaining the NEE response to rain events than rain characteristics and changes in water availability. This suggests that peatland CO2 uptake is highly sensitive to changes in cloud cover formation and to altered rainfall regimes, a process hitherto largely

Electromagnetic Drop Scale Scattering Modelling for Dynamic Statistical Rain Fields

OpenAIRE

Hipp, Susanne

2015-01-01

This work simulates the scattering of electromagnetic waves by a rain field. The calculations are performed for the individual drops and accumulate to a time signal dependent on the dynamic properties of the rain field. The simulations are based on the analytical Mie scattering model for spherical rain drops and the simulation software considers the rain characteristics drop size (including their distribution in rain), motion, and frequency and temperature dependent permittivity. The performe...

The intensity of precipitation during extratropical cyclones in global warming simulations: a link to cyclone intensity?

Energy Technology Data Exchange (ETDEWEB)

Watterson, I.G. [CSIRO Atmospheric Research, Aspendale (Australia)

2006-01-01

Simulations of global warming over the coming century from two CSIRO GCMs are analysed to assess changes in the intensity of extratropical cyclones, and the potential role of increased latent heating associated with precipitation during cyclones. A simple surface cyclone detection scheme is applied to a four-member ensemble of simulations from the Mark 2 GCM, under rising greenhouse gas concentrations. The seasonal distribution of cyclones appears broadly realistic during 1961-1990. By 2071-2100, with 3 K global warming, numbers over 20 deg N to 70 deg N decrease by 6% in winter and 2% annually, with similar results for the south. The average intensity of cyclones, from relative central pressure and other measures, is largely unchanged however. 30-yr extremes of dynamic intensity also show little clear change, including values averaged over continents. Mean rain rates at cyclone centres are typically at least double rates from all days. Rates during cyclones increase by an average 14% in the northern winter under global warming. Rates over adjacent grid squares and during the previous day increase similarly, as do extreme rates. Results from simulations of the higher-resolution (1.8 deg grid) Mark 3 GCM are similar, with widespread increases in rain rates but not in cyclone intensity. The analyses suggest that latent heating during storms increases, as anticipated due to the increased moisture capacity of the warmer atmosphere. However, any role for enhanced heating in storm development in the GCMs is apparently masked by other factors. An exception is a 5% increase in extreme intensity around 55 deg S in Mark 3, despite decreased numbers of lows, a factor assessed using extreme value theory. Further studies with yet higher-resolution models may be needed to examine the potential realism of these results, particularly with regard to extremes at smaller scale.

Rain events and their effect on effluent quality studied at a full scale activated sludge treatment plant.

Science.gov (United States)

Wilén, B M; Lumley, D; Mattsson, A; Mino, T

2006-01-01

The effect of rain events on effluent quality dynamics was studied at a full scale activated sludge wastewater treatment plant which has a process solution incorporating pre-denitrification in activated sludge with post-nitrification in trickling filters. The incoming wastewater flow varies significantly due to a combined sewer system. Changed flow conditions have an impact on the whole treatment process since the recirculation to the trickling filters is set by the hydraulic limitations of the secondary settlers. Apart from causing different hydraulic conditions in the plant, increased flow due to rain or snow-melting, changes the properties of the incoming wastewater which affects process performance and effluent quality, especially the particle removal efficiency. A comprehensive set of on-line and laboratory data were collected and analysed to assess the impact of rain events on the plant performance.

[Dynamics of seed rain of Tripterygium hypoglaucum and soil seed bank].

Science.gov (United States)

Zhang, Zhi-Wei; Wei, Yong-Sheng; Liu, Xiang; Su, Shu; Qu, Xian-You; Wang, Chang-Hua

2017-11-01

Tripterygium hypoglaucum is an endangered species in arid areas of Xiannvshan Chongqing, China. The dynamic characteristics of seed rain and soil seed bank of T. hypoglaucum were studied in this paper．Results showed that T. hypoglaucum years of mature seeds distribution number up to October; the seed rain occurred from the last ten-day of September to in the first ten-day of November and the peak of scattered seed rain concentrated in the October．The numbers of soil seed bank at 2-5 cm soil layer,mainly concentrated in the 1.5-3.5 m range. T. hypoglaucum seeds to the wind as a force for transmission, the transmission ability is strong, but in the process of natural reproduction, full mature seed rate is low, the soil seed bank seeds seed short-lived factors these were unfavorable for the natural reproduction of T. hypoglaucum population. Copyright© by the Chinese Pharmaceutical Association.

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

Directory of Open Access Journals (Sweden)

S. Westermann

2011-10-01

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

Phenology of seed and leaves rain in response to periodic climatic variability in a seasonal wet tropical forest

Science.gov (United States)

Matteo, D.; Wright, S. J.; Davies, S. J.; Muller-Landau, H. C.; Wolfe, B.; Detto, M.

2016-12-01

Phenology, by controlling the rhythms of plants, plays a fundamental role in regulating access to resources, ecosystem processes, competition among species, interactions with consumers and feedbacks to the climate. In high biodiverse tropical forests, where phenology of flowering and leafing are complex, an adequate representation of phenology must take into account a given set of climatic, edaphic and biotic factors. Climatic factors are particularly important because plants may use them as cues for timing different phenological phases and be influenced by their intensity. Climatic variability can be periodic, if events occur with regular frequency, or aperiodic. One prominent periodic large-scale pattern that causes unusual weather is ENSO event. In general, Central America tends to be dry and warm during a mature phase of an ENSO event, which usually peaks between October and January with a frequency of 2-3 events per decade. Because in many tropical areas the effect of ENSO is highly prominent, it is plausible that plants have adapted their growth and reproduction mechanisms to synchronize ENSO phases, in a similar way that plants do during the seasonal cycle. We used a long dataset (30+ years) of fruits and leaves rains of tropical trees and lianas to determine ecosystem response and species specific response of these phenological events to local climate variability corresponding to the modes of ENSO. Specifically, we tested the hypothesis that phenological responses to ENSO are similar to response to seasonal cycles, i.e., higher litterfall before a warm-dry phase and higher fruiting after such phase, with strong correlation between seeds and leaves. At sub-community level, we evaluated whether evergreen and deciduous, biotic and abiotic dispersers and free and climbing life forms, have the same response to ENSO in terms of leaves and seeds rain. At species level we tested the hypothesis that species with low photosynthetic capacity leaves are more responsive

Processes of Change in Acceptance and Commitment Therapy and Cognitive Therapy for Depression: A Mediation Reanalysis of Zettle and Rains

Science.gov (United States)

Zettle, Robert D.; Rains, Jeanetta C.; Hayes, Steven C.

2011-01-01

Several articles have recently questioned the distinction between acceptance and commitment therapy (ACT) and traditional cognitive therapy (CT). This study presents a reanalysis of data from Zettle and Rains that compared 12 weeks of group CT with group ACT. For theoretical reasons, Zettle and Rains also included a modified form of CT that did…

Scalable, Economical Fabrication Processes for Ultra-Compact Warm-White LEDs

Energy Technology Data Exchange (ETDEWEB)

Lowes, Ted [Cree, Inc., Durham, NC (United States)

2016-01-31

Conventional warm-white LED component fabrication consists of a large number of sequential steps which are required to incorporate electrical, mechanical, and optical functionality into the component. Each of these steps presents cost and yield challenges which multiply throughout the entire process. Although there has been significant progress in LED fabrication over the last decade, significant advances are needed to enable further reductions in cost per lumen while not sacrificing efficacy or color quality. Cree conducted a focused 18-month program to develop a new low-cost, high-efficiency light emitting diode (LED) architecture enabled by novel large-area parallel processing technologies, reduced number of fabrication steps, and minimized raw materials use. This new scheme is expected to enable ultra-compact LED components exhibiting simultaneously high efficacy and high color quality. By the end of the program, Cree fabricated warm-white LEDs with a room-temperature “instant on” efficacy of >135 lm/W at ~3500K and 90 CRI (when driven at the DOE baseline current density of 35 A/cm2). Cree modified the conventional LED fabrication process flow in a manner that is expected to translate into simultaneously high throughput and yield for ultra-compact packages. Building on its deep expertise in LED wafer fabrication, Cree developed these ultra-compact LEDs to have no compromises in color quality or efficacy compared to their conventional counterparts. Despite their very small size, the LEDs will also be robustly electrically integrated into luminaire systems with the same attach yield as conventional packages. The versatility of the prototype high-efficacy LED architecture will likely benefit solid-state lighting (SSL) luminaire platforms ranging from bulbs to troffers. We anticipate that the prototype LEDs will particularly benefit luminaires with large numbers of distributed compact packages, such as linear and area luminaires (e.g. troffers). The fraction of

Acid Rain. LC Science Tracer Bullet.

Science.gov (United States)

Hollmann, Pauline, Comp.

The term "acid rain," also called "acid precipitation," generally refers to any precipitation having a pH value of less than 5.6. This guide to the literature on acid rain in the collections of the Library of Congress is not necessarily intended to be a comprehensive bibliography. It is designed to provide the reader with a set…

Effects of phosphorus and nitrogen additions on tropical soil microbial activity in the context of experimental warming

Science.gov (United States)

Foley, M.; Nottingham, A.; Turner, B. L.

2017-12-01

Soil warming is generally predicted to increase microbial mineralization rates and accelerate soil C losses which could establish a positive feedback to climatic warming. Tropical rain forests account for a third of global soil C, yet the responseto of tropical soil C a warming climate remains poorly understood. Despite predictions of soil C losses, decomposition of soil organic matter (SOM) in tropical soils may be constrained by several factors including microbial nutrient deficiencies. We performed an incubation experiment in conjunction with an in-situ soil warming experiment in a lowland tropical forest on Barro Colorado Island, Panama, to measure microbial response to two key nutrient additions in shallow (0-10cm) and deep (50-100 cm) soils. We compared the response of lowland tropical soils to montane tropical soils, predicting that lowland soils would display the strongest response to phosphorus additions. Soils were treated with either carbon alone (C), nitrogen (CN), phosphorus (CP) or nitrogen and phosphorus combined (CNP). Carbon dioxide (CO2) production was measured by NaOH capture and titrimetric analysis for 10 days. Cumulative CO2 production in montane soils increased significantly with all additions, suggesting these soils are characterized by a general microbial nutrient deficiency. The cumulative amount of C respired in deep soils from the lowland site increased significantly with CP and CNP additions, suggesting that microbial processes in deep lowland tropical soils are phosphorus-limited. These results support the current understanding that lowland tropical forests are growing on highly weathered, phosphorus-deplete soils, and provide novel insight that deep tropical SOM may be stabilized by a lack of biologically-available phosphorus. Further, this data suggests tropical soil C losses under elevated temperature may be limited by a strong microbial phosphorus deficiency.

State regulatory issues in acid rain compliance

International Nuclear Information System (INIS)

Solomon, B.D.; Brick, S.

1992-01-01

This article discusses the results of a US EPA workshop for state regulators and commission staff on acid rain compliance concerns. The topics of the article include the results of market-based emissions control, how emissions trading is expected to reduce emissions, public utility commissions approval of compliance plans, the purposes of the workshop, market information, accounting issues, regulatory process and utility planning, multi-state compliance planning, and relationship to other compliance issues

Explosive Chromospheric Evaporation and Warm Rain in a GOES C3 Flare Observed by IRIS, Hinode/EIS, and RHESSI

Science.gov (United States)

Brosius, J. W.; Inglis, A. R.

2017-12-01

IRIS and Hinode/EIS observed a C3.1 flare in AR 12002 in stare mode on 2014 March 15.GOES observed the flare to start at 00:21:35 UT and peak at 00:26:30 UT. The IRIS slitwas pointed near the center of the flare while the EIS slit was pointed 35 arcsec westof the IRIS slit. About 4 minutes before the GOES flare start, the C II and Si IV lineintensities observed by IRIS became (and remained) significantly greater than theirpre-flare average values; this indicates that the flare had begun and that thechromosphere and transition region were involved. IRIS first detected significant,blueshifted Fe XXI emission at 00:22:42 UT, by which time the C II and Si IV lineintensities had increased by factors around 100 and their profiles were significantlyredshifted. This combination of simultaneous, cospatial blueshifted Fe XXI emissionwith redshifted C II and Si IV emission indicates explosive chromospheric evaporation.SDO's HMI observed a localized area of enhanced magnetic field strength toward thesouthernmost portion of the EIS slit's position that appears to be connected to theflare site by faint loops evident in AIA 131 A emission. EIS spectra at this locationreveal intensity enhancements by factors up to about 1.7 in the Fe XIV and Fe XVI lineemission, and the emergence of faint Fe XXIII emission that is too weak to measurevelocities. Emission lines from the two coronal ions show redshifts of about 9 km/saround 00:24:00 UT. The density sensitive line intensity ratio of Fe XIV 264.7/274.2observed by EIS reveals an increase of electron density from (1.03+/-0.20)X10^9 /cm^3before the flare to (3.58+/-0.68)X10^9 /cm^3 during the flare. This combination ofredshifted coronal line emission and increased coronal electron density is consistentwith explosively evaporated flare material observed by IRIS falling as warm rain andaccumulating in the remote area observed by EIS. A thermal/nonthermal fit to the hardX-ray spectrum observed by RHESSI yields a nonthermal energy injection

Influence of Simulated Acid Rain Corrosion on the Uniaxial Tensile Mechanical Properties of Concrete

Directory of Open Access Journals (Sweden)

Ying-zi Zhang

2012-01-01

Full Text Available An experimental study on the uniaxial tensile property of concrete exposed to the acid rain environment was carried out. Acid rain with pH level of 1.0 was deposed by the mixture of sulfate and nitric acid solution in the laboratory. Dumbbell-shaped concrete specimens were immersed in the simulated acid rain completely. After being exposed to the deposed mixture for a certain period, uniaxial tensile test was performed on the concrete specimens. The results indicate that elastic modulus, tensile strength, and peak strain have a slight increase at the initial corrosion stage, and with the extension of corrosion process, elastic modulus and tensile strength decrease gradually, while the peak strain still increases. It is found that the compressive strength is more sensitive than the tensile strength in aggressive environment. Based on the experimental results, an equation was proposed to describe the ascending branch of the stress-strain curve of the concrete corroded by acid rain.

A stochastic fractional dynamics model of space-time variability of rain

Science.gov (United States)

Kundu, Prasun K.; Travis, James E.

2013-09-01

varies in space and time in a highly irregular manner and is described naturally in terms of a stochastic process. A characteristic feature of rainfall statistics is that they depend strongly on the space-time scales over which rain data are averaged. A spectral model of precipitation has been developed based on a stochastic differential equation of fractional order for the point rain rate, which allows a concise description of the second moment statistics of rain at any prescribed space-time averaging scale. The model is thus capable of providing a unified description of the statistics of both radar and rain gauge data. The underlying dynamical equation can be expressed in terms of space-time derivatives of fractional orders that are adjusted together with other model parameters to fit the data. The form of the resulting spectrum gives the model adequate flexibility to capture the subtle interplay between the spatial and temporal scales of variability of rain but strongly constrains the predicted statistical behavior as a function of the averaging length and time scales. We test the model with radar and gauge data collected contemporaneously at the NASA TRMM ground validation sites located near Melbourne, Florida and on the Kwajalein Atoll, Marshall Islands in the tropical Pacific. We estimate the parameters by tuning them to fit the second moment statistics of radar data at the smaller spatiotemporal scales. The model predictions are then found to fit the second moment statistics of the gauge data reasonably well at these scales without any further adjustment.

40 CFR 76.3 - General Acid Rain Program provisions.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

Acid rain. Les pluies acides

Energy Technology Data Exchange (ETDEWEB)

Curren, T

1979-11-28

This report was produced for the use of Members of Parliament and House of Commons committees. The document describes the formation of acid rain, emissions of acidifying pollutants in North America, the growth of the problem and its environmental effects on aquatic and terrestrial ecosystems, human health and man-made structures. Areas of Canada which are most susceptible are identified. Actions taken by Parliament are given, including the formation of a sub-committee on acid rain and the passing of Bill C-51 in 1980 to amend the Clean Air Act, bringing it closer to a similar law in the U.S. A chronology of government responses to acid rain at the international, national and provincial level, is given. The most recent government actions included the passing of the US Clean Air Act by the Senate, the amending of the act into law, and commencement of negotiations to develop a Canada-US Air Quality Accord. 10 refs.

Effect of soil warming and rainfall patterns on soil N cycling in northern Europe

DEFF Research Database (Denmark)

Patil, Raveendra Hanumantagoud; Lægdsmand, Mette; Olesen, Jørgen Eivind

2010-01-01

. These changes may affect soil moisture regimes, soil water drainage, soil nitrogen (N) availability and N leaching to aquatic environment and N2O emissions to atmosphere. Thus it is important to study the effects of increased soil temperature and varying rainfall patterns on soil N cycling in arable land from...... temperate climates, which is a major source of N pollution. An open-field lysimeter study was carried out during 2008-2009 in Denmark on loamy sand soil (Typic Hapludult) with three factors: number of rainy days, rainfall amount and soil warming. Number of rainy days included the mean monthly rainy days...... by 5 °C at 0.1 m depth as ‘heated' and non-heated as ‘control' treatments. Automated mobile rain-out shelter and irrigation system, and insulated buried heating cables were used to impose the treatments. Soil warming, compared with unheated control, advanced winter wheat crop development, and increased...

Irrigation enhances local warming with greater nocturnal warming effects than daytime cooling effects

Science.gov (United States)

Chen, Xing; Jeong, Su-Jong

2018-02-01

To meet the growing demand for food, land is being managed to be more productive using agricultural intensification practices, such as the use of irrigation. Understanding the specific environmental impacts of irrigation is a critical part of using it as a sustainable way to provide food security. However, our knowledge of irrigation effects on climate is still limited to daytime effects. This is a critical issue to define the effects of irrigation on warming related to greenhouse gases (GHGs). This study shows that irrigation led to an increasing temperature (0.002 °C year-1) by enhancing nighttime warming (0.009 °C year-1) more than daytime cooling (-0.007 °C year-1) during the dry season from 1961-2004 over the North China Plain (NCP), which is one of largest irrigated areas in the world. By implementing irrigation processes in regional climate model simulations, the consistent warming effect of irrigation on nighttime temperatures over the NCP was shown to match observations. The intensive nocturnal warming is attributed to energy storage in the wetter soil during the daytime, which contributed to the nighttime surface warming. Our results suggest that irrigation could locally amplify the warming related to GHGs, and this effect should be taken into account in future climate change projections.

Performance of a piezoelectric energy harvester in actual rain

International Nuclear Information System (INIS)

Wong, Voon-Kean; Ho, Jee-Hou; Chai, Ai-Bao

2017-01-01

When raindrops impact on the surface of a piezoelectric beam, strain energy produced by the impinging raindrop will be converted to harvestable electrical energy by the piezoelectric layers in a cantilever beam. The novelty of this study is to investigate the performance of the harvester in actual rain and provide practical insights on implementation. The influences of rain parameters such as rain rate, rainfall depth, raindrop count, and drop size distribution (DSD) are discussed in this study. The raindrops accumulated on the surface of the piezoelectric beam will form a water layer. It is described using added mass coefficient in this study. In an actual rain experiment, a piezoelectric beam with surface area of 0.0018 m 2 is able to produce 2076 μJ of energy over a duration of 301 min. The energy generation of a raindrop impact piezoelectric energy harvester is highly dependent on the rain rate. Due to the inconsistency of the energy generation, the piezoelectric energy harvester would require an integration of suitable energy storage device for continuous operation. Nevertheless, this work shows the feasibility of harvesting raindrop energy using a piezoelectric beam. - Highlights: • The performance of a piezoelectric rain energy harvester is tested in actual rain. • The energy generation is highly dependent on the rain rate. • Practical insights on the implementation of the harvester are discussed. • A total energy of 2076 μJ is generated over a duration of 301 min.

Isotopic equilibrium between precipitation and water vapor: evidence from continental rains in central Kenya

Science.gov (United States)

Soderberg, K.; Gerlein, C.; Kemeny, P. C.; Caylor, K. K.

2013-12-01

An accurate understanding of the relationships between the isotopic composition of liquid water and that of water vapor in the environment can help describe hydrologic processes across many scales. One such relationship is the isotopic equilibrium between falling raindrops and the surrounding vapor. The degree of equilibration is used to model the isotopic composition of precipitation in isotope-enable general circulation models and land-atmosphere exchange models. Although this equilibrium has been a topic of isotope hydrology research for more than four decades, few studies have included vapor measurements to validate modeling efforts. Recent advances in laser technology have allowed for in situ vapor measurements at high temporal resolution (e.g., >1 Hz). Here we present concomitant rain and vapor measurements for a series of 17 rain events during the 'Continental' rainy season (June through August) at Mpala Research Center in central Kenya. Rain samples (n=218) were collected at intervals of 2 to 35 minutes (median of 3 minutes) depending on the rain rate (0.4 to 10.5 mm/hr). The volume-weighted mean rain values for δ18O, δ2H and D-excess (δ2H - 8* δ18O) were 0.1 ‰, 10.7 ‰, and 10.1 ‰. These values are more enriched than the annual weighted means reported for the area (-2.2 ‰, -7.6 ‰, and 11.0 ‰, respectively). Vapor was measured continuously at ~2Hz (DLT-100, Los Gatos Research), with an inverted funnel intake 4m above the ground surface. The mean vapor isotopic composition during the rain events was -10.0 +/- 1.2 ‰ (1 σ) for δ18O and -73.9 +/- 7.0 ‰ for δ2H. The difference between the rain sample isotopic composition and that of liquid in isotopic equilibrium with the corresponding vapor at the ambient temperature was 0.8 +/- 2.2 ‰ for δ18O and 6.2 +/- 7.0 ‰ for δ2H. This disequilibrium was found to correlate with the natural log of rain rate (R2 of 0.26 for δ18O and 0.46 for δ2H), with lower rain rates having larger

Spatial variability and trends of the rain intensity over Greece

Science.gov (United States)

Kambezidis, H. D.; Larissi, I. K.; Nastos, P. T.; Paliatsos, A. G.

2010-07-01

In this study, the spatial and temporal variability of the mean annual rain intensity in Greece are examined during a 41-year period (1962-2002). The meteorological datasets concern monthly rain amounts (mm) and the respective monthly durations (h) recorded at thirty two meteorological stations of the Hellenic National Meteorological Service, which are uniformly distributed on Greek territory, in order to calculate the mean monthly rain intensity. All the rain time series used in the analysis were tested by the application of the short-cut Bartlett test of homogeneity. The spatial distribution of the mean annual rain intensity is studied using the Kriging interpolation method, while the temporal variability, concerning the mean annual rain intensity trends along with their significance (Mann-Kendall test), is analysed. The findings of the analysis show that statistically significant negative trends (95% confidence level) appear mainly in the west sub-regions of Greece, while statistically significant positive trends (95% confidence level) appear in the wider area of Athens and the complex of Cyclades Islands. Further analysis concerning the seasonal rain intensity is needed, because there are different seasonal patterns, taking into account that, convective rain in Greece occurs mainly within the summer season.

Rain forest provides pollinating beetles for atemoya crops.

Science.gov (United States)

Blanche, Rosalind; Cunningham, Saul A

2005-08-01

Small beetles, usually species of Nitidulidae, are the natural pollinators of atemoya (Annona squamosa L. x A. cherimola Mill. hybrids; custard apple) flowers but commercial atemoya growers often need to carry out labor-intensive hand pollination to produce enough high-quality fruit. Because Australian rain forest has plant species in the same family as atemoya (Annonaceae) and because many rain forest plants are beetle pollinated, we set out to discover whether tropical rain forest in far north Queensland harbors beetles that could provide this ecosystem service for atemoya crops. Orchards were chosen along a gradient of increasing distance from tropical rain forest (0.1-24 km). We sampled 100 flowers from each of nine atemoya orchards and determined the identity and abundance of insects within each flower. To assess the amount of pollination due to insects, we bagged six flowers per tree and left another six flowers per tree accessible to insects on 10 trees at an orchard near rain forest. Results indicated that atemoya orchards pollinators that are likely to originate in tropical rain forest. These native beetles occurred reliably enough in crops near rain forest to have a positive effect on the quantity of fruit produced but their contribution was not great enough to satisfy commercial production needs. Management changes, aimed at increasing native beetle abundance in crops, are required before these beetles could eliminate the need for growers to hand pollinate atemoya flowers. Appreciation of the value of this resource is necessary if we are to develop landscapes that both conserve native biodiversity and support agricultural production.

Human Ecology: Acid Rain and Public Policy.

Science.gov (United States)

Bybee, Rodger W.

1983-01-01

A connection between science and society can be seen in the human and ecological dimensions of one contemporary problem: acid rain. Introduces a human ecological theme and relationships between acid rain and public policy, considering scientific understanding and public awareness, scientific research and public policy, and national politics and…

A statistical rain attenuation prediction model with application to the advanced communication technology satellite project. 3: A stochastic rain fade control algorithm for satellite link power via non linear Markow filtering theory

Science.gov (United States)

Manning, Robert M.

1991-01-01

The dynamic and composite nature of propagation impairments that are incurred on Earth-space communications links at frequencies in and above 30/20 GHz Ka band, i.e., rain attenuation, cloud and/or clear air scintillation, etc., combined with the need to counter such degradations after the small link margins have been exceeded, necessitate the use of dynamic statistical identification and prediction processing of the fading signal in order to optimally estimate and predict the levels of each of the deleterious attenuation components. Such requirements are being met in NASA's Advanced Communications Technology Satellite (ACTS) Project by the implementation of optimal processing schemes derived through the use of the Rain Attenuation Prediction Model and nonlinear Markov filtering theory.

Real-Time Rain Rate Evaluation via Satellite Downlink Signal Attenuation Measurement.

Science.gov (United States)

Giannetti, Filippo; Reggiannini, Ruggero; Moretti, Marco; Adirosi, Elisa; Baldini, Luca; Facheris, Luca; Antonini, Andrea; Melani, Samantha; Bacci, Giacomo; Petrolino, Antonio; Vaccaro, Attilio

2017-08-12

We present the NEFOCAST project (named by the contraction of "Nefele", which is the Italian spelling for the mythological cloud nymph Nephele, and "forecast"), funded by the Tuscany Region, about the feasibility of a system for the detection and monitoring of precipitation fields over the regional territory based on the use of a widespread network of new-generation Eutelsat "SmartLNB" (smart low-noise block converter) domestic terminals. Though primarily intended for interactive satellite services, these devices can also be used as weather sensors, as they have the capability of measuring the rain-induced attenuation incurred by the downlink signal and relaying it on an auxiliary return channel. We illustrate the NEFOCAST system architecture, consisting of the network of ground sensor terminals, the space segment, and the service center, which has the task of processing the information relayed by the terminals for generating rain field maps. We discuss a few methods that allow the conversion of a rain attenuation measurement into an instantaneous rainfall rate. Specifically, we discuss an exponential model relating the specific rain attenuation to the rainfall rate, whose coefficients were obtained from extensive experimental data. The above model permits the inferring of the rainfall rate from the total signal attenuation provided by the SmartLNB and from the link geometry knowledge. Some preliminary results obtained from a SmartLNB installed in Pisa are presented and compared with the output of a conventional tipping bucket rain gauge. It is shown that the NEFOCAST sensor is able to track the fast-varying rainfall rate accurately with no delay, as opposed to a conventional gauge.

Acid rain may cause senile dementia

Energy Technology Data Exchange (ETDEWEB)

Pearce, F

1985-04-25

Aluminium, released from the soil by acid rain, may be a cause of several forms of senile dementia including Parkinson's disease and Alzheimer's disease. Many upland reservoirs, fed by acid rain, supply homes with water laced with significant amounts of aluminium. Studies in the Pacific have shown that communities living on soils that are extremely rich in bauxite, the rock containing aluminium, have a very high incidence of Alzheimer's disease.

I like riding my bike. If it doesn't rain of course'. Accounts of embodied practices of rain in the face of climate change

DEFF Research Database (Denmark)

Lindegaard, Laura Bang

. Secondly, the paper focuses more thoroughly on conceptualisations of cycling in rain by showing how rain is used in making socially legitimate meanings of everyday transportation practices. It shows the subtle ways in which matters of rain are used as justifications for not biking. It also shows...

SMAP Salinity Artifacts Associated With Presence of Rain

Science.gov (United States)

Jacob, M. M.; Santos-Garcia, A.; Jones, L.

2016-02-01

The Soil Moisture Active Passive (SMAP) satellite carries an L-band radiometer, which measures sea surface salinity (SSS) over a swath of 1000 km @ 40 km resolution. SMAP can extend the Aquarius (AQ) salinity data record with improved temporal/spatial sampling. Previous studies [see references] have demonstrated significant differences between satellite and in-situ salinity measurements during rain. In the presence of precipitation, salinity stratification exists near the sea surface, which nullifies the presumption of a well-mixed salinity. In general, these salinity gradients last only a few hours and the upper layer becomes slightly fresher in salinity. This paper describes the Rain Impact Model (RIM) that simulates the effects of rain accumulation on the SSS [Santos-Garcia et al., 2014] applied to SMAP. This model incorporates rainfall information for the previous 24 hours to the measurement sample (in this case SMAP) and uses as initialization the Hybrid Coordinate Ocean Model (HYCOM) data. Given the better resolution of SMAP, the goal of this paper is to continue the analysis previously done with AQ to better understand the effects of the instantaneous and accumulated rain on the salinity measurements. Boutin, J., N. Martin, G. Reverdin, X. Yin, and F. Gaillard (2013), Sea surface freshening inferred from SMOS and ARGO salinity: Impact of rain, Ocean Sci., 9(1), 183-192, doi:10.5194/os-9-183-2013. Santos-Garcia, A., M. Jacob, L. Jones, W. Asher, Y. Hejazin, H. Ebrahimi, and M. Rabolli (2014), Investigation of rain effects on Aquarius Sea Surface Salinity measurements, J. Geophys. Res. Oceans, 119, 7605-7624, doi:10.1002/2014JC010137. Tang, W., S.H Yueh, A. Hayashi, A.G. Fore, W.L. Jones, A. Santos-Garcia, and M.M. Jacob, (2015), Rain-Induced Near Surface Salinity Stratification and Rain Roughness Correction for Aquarius SSS Retrieval, in Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of, 8(99), 1-11, doi: 10.1109/JSTARS.2015.2463768.

Recently amplified arctic warming has contributed to a continual global warming trend

Science.gov (United States)

Huang, Jianbin; Zhang, Xiangdong; Zhang, Qiyi; Lin, Yanluan; Hao, Mingju; Luo, Yong; Zhao, Zongci; Yao, Yao; Chen, Xin; Wang, Lei; Nie, Suping; Yin, Yizhou; Xu, Ying; Zhang, Jiansong

2017-12-01

The existence and magnitude of the recently suggested global warming hiatus, or slowdown, have been strongly debated1-3. Although various physical processes4-8 have been examined to elucidate this phenomenon, the accuracy and completeness of observational data that comprise global average surface air temperature (SAT) datasets is a concern9,10. In particular, these datasets lack either complete geographic coverage or in situ observations over the Arctic, owing to the sparse observational network in this area9. As a consequence, the contribution of Arctic warming to global SAT changes may have been underestimated, leading to an uncertainty in the hiatus debate. Here, we constructed a new Arctic SAT dataset using the most recently updated global SATs2 and a drifting buoys based Arctic SAT dataset11 through employing the `data interpolating empirical orthogonal functions' method12. Our estimate of global SAT rate of increase is around 0.112 °C per decade, instead of 0.05 °C per decade from IPCC AR51, for 1998-2012. Analysis of this dataset shows that the amplified Arctic warming over the past decade has significantly contributed to a continual global warming trend, rather than a hiatus or slowdown.

Improved Gradation for Rain Garden of Low Impact Development

Science.gov (United States)

Lee, Sandra; Chang, Fu-Ming

2016-04-01

With rapid urban and economic development, living standard improves in urban areas but urban ecological environments deteriorate rapidly. Urban waterlogging and flooding have become a serious problem for urban water security. As urbanization continues, sustainability is the key to balance between urban development and healthy environment. Rain garden is recommended to be one of the best ways to reduce urban pollutants. It not only diminishes runoff flooding but also purify water in the urban area. The studies on rain gardens are mainly about how to incorporate rain garden to purify water quality, but lack of researches on runoff control. This project focuses on rain garden under Low Impact Development using indoor laboratory to test and quantify the water holding capacities of two different Taiwan indigenous rain garden plants, Taiwan Cyclosorus and Sour Grass. The results show that the water holding capacity of Sour Grass (10%-37%) is better than that of Taiwan Cyclosorus (6.8%-17.3%). The results could be a helpful reference for Low Impact Development in urban flood prevention and urban planning. Keywords: Low Impact Development; rain garden; indoor laboratory experiments; water holding capacity; porosity

Characteristics of rain penetration through a gravity ventilator used for natural ventilation.

Science.gov (United States)

Kim, Taehyeung; Lee, Dong Ho; Ahn, Kwangseog; Ha, Hyunchul; Park, Heechang; Piao, Cheng Xu; Li, Xiaoyu; Seo, Jeoungyoon

2008-01-01

Gravity ventilators rely simply on air buoyancy to extract air and are widely used to exhaust air contaminants and heat from workplaces using minimal energy. They are designed to maximize the exhaust flow rate, but the rain penetration sometimes causes malfunctioning. In this study, the characteristics of rain penetration through a ventilator were examined as a preliminary study to develop a ventilator with the maximum exhaust capacity while minimizing rain penetration. A model ventilator was built and exposed to artificial rain and wind. The paths, intensities and amounts of penetration through the ventilator were observed and measured in qualitative and quantitative fashions. In the first phase, the pathways and intensities of rain penetration were visually observed. In the second phase, the amounts of rain penetration were quantitatively measured under the different configurations of ventilator components that were installed based on the information obtained in the first-phase experiment. The effects of wind speed, grill direction, rain drainage width, outer wall height, neck height and leaning angle of the outer wall from the vertical position were analyzed. Wind speed significantly affected rain penetration. Under the low crosswind conditions, the rain penetration intensities were under the limit of detection. Under the high crosswind conditions, grill direction and neck height were the most significant factors in reducing rain penetration. The installation of rain drainage was also important in reducing rain penetration. The experimental results suggest that, with proper configurations of its components, a gravity ventilator can be used for natural ventilation without significant rain penetration problems.

Dust Rains Deliver Diverse Assemblages of Microorganisms to the Eastern Mediterranean

Science.gov (United States)

Itani, Ghida Nouhad; Smith, Colin Andrew

2016-03-01

Dust rains may be particularly effective at delivering microorganisms, yet their biodiversities have been seldom examined. During 2011 and 2012 in Beirut, Lebanon, 16 of 21 collected rainfalls appeared dusty. Trajectory modelling of air mass origins was consistent with North African sources and at least one Southwest Asian source. As much as ~4 g particulate matter, ~20 μg DNA, and 50 million colony forming units were found deposited per square meter during rainfalls each lasting less than one day. Sequencing of 93 bacteria and 25 fungi cultured from rain samples revealed diverse bacterial phyla, both Gram positive and negative, and Ascomycota fungi. Denaturing Gradient Gel Electrophoresis of amplified 16S rDNA of 13 rains revealed distinct and diverse assemblages of bacteria. Dust rain 16S libraries yielded 131 sequences matching, in decreasing order of abundance, Betaproteobacteria, Alphaproteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, Cyanobacteria, Epsilonproteobacteria, Gammaproteobacteria, and Deltaproteobacteria. Clean rain 16S libraries yielded 33 sequences matching only Betaproteobacteria family Oxalobacteraceae. Microbial composition varied between dust rains, and more diverse and different microbes were found in dust rains than clean rains. These results show that dust rains deliver diverse communities of microorganisms that may be complex products of revived desert soil species and fertilized cloud species.

Rain Fade Compensation for Ka-Band Communications Satellites

Science.gov (United States)

Mitchell, W. Carl; Nguyen, Lan; Dissanayake, Asoka; Markey, Brian; Le, Anh

1997-01-01

This report provides a review and evaluation of rain fade measurement and compensation techniques for Ka-band satellite systems. This report includes a description of and cost estimates for performing three rain fade measurement and compensation experiments. The first experiment deals with rain fade measurement techniques while the second one covers the rain fade compensation techniques. The third experiment addresses a feedback flow control technique for the ABR service (for ATM-based traffic). The following conclusions were observed in this report; a sufficient system signal margin should be allocated for all carriers in a network, that is a fixed clear-sky margin should be typically in the range of 4-5 dB and should be more like 15 dB in the up link for moderate and heavy rain zones; to obtain a higher system margin it is desirable to combine the uplink power control technique with the technique that implements the source information rate and FEC code rate changes resulting in a 4-5 dB increase in the dynamic part of the system margin. The experiments would assess the feasibility of the fade measurements and compensation techniques, and ABR feedback control technique.

Potential Predictability of the Sea-Surface Temperature Forced Equatorial East Africa Short Rains Interannual Variability in the 20th Century

Science.gov (United States)

Bahaga, T. K.; Gizaw, G.; Kucharski, F.; Diro, G. T.

2014-12-01

In this article, the predictability of the 20th century sea-surface temperature (SST) forced East African short rains variability is analyzed using observational data and ensembles of long atmospheric general circulation model (AGCM) simulations. To our knowledge, such an analysis for the whole 20th century using a series of AGCM ensemble simulations is carried out here for the first time. The physical mechanisms that govern the influence of SST on East African short rains in the model are also investigated. It is found that there is substantial skill in reproducing the East African short rains variability, given that the SSTs are known. Consistent with previous recent studies, it is found that the Indian Ocean and in particular the western pole of the Indian Ocean dipole (IOD) play a dominant role for the prediction skill, whereas SSTs outside the Indian Ocean play a minor role. The physical mechanism for the influence of the western Indian Ocean on East African rainfall in the model is consistent with previous findings and consists of a gill-type response to a warm (cold) anomaly that induces a westerly(easterly) low-level flow anomaly over equatorial Africa and leads to moisture flux convergence (divergence) over East Africa. On the other hand, a positive El Nino-Southern Oscillation (ENSO) anomaly leads to a spatially non-coherent reducing effect over parts of East Africa, but the relationship is not strong enough to provide any predictive skill in our model. The East African short rains prediction skill is also analyzed within a model-derived potential predictability framework and it is shown that the actual prediction skill is broadly consistent with the model potential prediction skill. Low-frequency variations of the prediction skill are mostly related to SSTs outside the Indian Ocean region and are likely due to an increased interference of ENSO with the Indian Ocean influence on East African short rains after the mid-1970s climate shift.

Foliar nutrient status of Pinus ponderosa exposed to ozone and acid rain

International Nuclear Information System (INIS)

Anderson, P.D.; Houpis, J.L.J.

1991-01-01

A direct effect of foliar exposure to acid rain may be increased leaching of nutrient elements. Ozone exposure, through degradation of the cuticle and cellular membranes, may also result in increased nutrient leaching. To test these hypotheses, the foliar concentrations of 13 nutrient elements were monitored for mature branches of three clones of Pinus ponderosa exposed to ozone and/or acid rain. The three clones represented three distinct levels of phenotypic vigor. Branches were exposed to charcoal filtered, ambient, or 2 x ambient concentrations of ozone and received no acid rain (NAP), pH 5.1 rain (5.1), or pH 3.0 (3.0) rain. Following 10 months of continuous ozone exposure and 3 months of weekly rain applications, the concentrations of P and Mg differed significantly among rain treatments with a ranking of: 5.1 < NAP < 3.0. The S concentration increased with rain application regardless of pH. For the clones of moderate and low vigor, the concentration of N decreased with increasing rain acidity. There was no evidence of significant ozone or ozone x acid rain response. Among the three families, high phenotypic vigor was associated with significantly greater concentrations of N, P, K, Mg, B and An. These results indicate generally negligible leaching as a result of exposure to acid rain and/or ozone for one growing season. Increases in foliar concentrations of S, Mg and P are possibly the result of evaporative surface deposition from the rain solution

Long range global warming

International Nuclear Information System (INIS)

Rolle, K.C.; Pulkrabek, W.W.; Fiedler, R.A.

1995-01-01

This paper explores one of the causes of global warming that is often overlooked, the direct heating of the environment by engineering systems. Most research and studies of global warming concentrate on the modification that is occurring to atmospheric air as a result of pollution gases being added by various systems; i.e., refrigerants, nitrogen oxides, ozone, hydrocarbons, halon, and others. This modification affects the thermal radiation balance between earth, sun and space, resulting in a decrease of radiation outflow and a slow rise in the earth's steady state temperature. For this reason the solution to the problem is perceived as one of cleaning up the processes and effluents that are discharged into the environment. In this paper arguments are presented that suggest, that there is a far more serious cause for global warming that will manifest itself in the next two or three centuries; direct heating from the exponential growth of energy usage by humankind. Because this is a minor contributor to the global warming problem at present, it is overlooked or ignored. Energy use from the combustion of fuels and from the output of nuclear reactions eventually is manifest as warming of the surroundings. Thus, as energy is used at an ever increasing rate the consequent global warming also increases at an ever increasing rate. Eventually this rate will become equal to a few percent of solar radiation. When this happens the earth's temperature will have risen by several degrees with catastrophic results. The trends in world energy use are reviewed and some mathematical models are presented to suggest future scenarios. These models can be used to predict when the global warming problem will become undeniably apparent, when it will become critical, and when it will become catastrophic

A review on wind-driven rain research in building science

NARCIS (Netherlands)

Blocken, B.J.E.; Carmeliet, J.E.

2004-01-01

Wind-driven rain (WDR) or driving rain is rain that is given a horizontal velocity component by the wind. WDR research is of importance in a number of research areas including earth sciences, meteorology and building science. Research methods and results are exchangeable between these domains but no

Flow Dynamics and Nutrient Reduction in Rain Gardens

Science.gov (United States)

The hydrological dynamics and changes in stormwater nutrient concentrations within rain gardens were studied by introducing captured stormwater runoff to rain gardens at EPA’s Urban Water Research Facility in Edison, New Jersey. The runoff used in these experiments was collected...

Acid rain legislation update

International Nuclear Information System (INIS)

Storey, H.L.

1990-01-01

This paper presents the author's view that the coal industry should develop a strategy to respond to the global warming issue. A few weeks ago a speaker stated that the global warming issue placed coal at the crossroads. He stated that global warming legislation, could reduce the consumption of coal by approximately twenty-five percent, without global warming legislation coal would continue to grow at a approximately three percent per year. It is believed there is a path to be traveled between the two options, legislation or no legislation, that can result in coal obtaining the position as the primary fuel source for electrical generating throughout the world. This is a path the coal industry can define and should follow

Thinking in the Rain.

Science.gov (United States)

Bartlett, Albert A.

1989-01-01

Four questions related to rain concerning aerodynamic drag force, pressure from the impact of raindrops, impact of wind on the pressure, and stopping force extended on the car by the water are proposed. (YP)

The erosion of carbonate stone by acid rain: Laboratory and field investigations

Science.gov (United States)

Baedecker, P.A.; Reddy, M.M.

1993-01-01

One of the goals of research on the effects of acidic deposition on carbonate stone surfaces is to define the incremental impact of acidic deposition relative to natural weathering processes on the rate of carbonate stone erosion. If rain that impacts carbonate stone surfaces is resident on the surface long enough to approach chemical equilibrium, the incremental effect of hydrogen ion is expected to be small (i.e., 6% for a rain of pH 4.0). Under nonequilibrium (i.e., high flow rate) conditions, kinetic considerations suggest that the incremental effect of hydrogen ion deposition could be quite significant. Field run-off experiments involving the chemical analysis of rain collected from inclined stone slabs have been used to evaluate stone dissolution processes under ambient conditions of wet and dry deposition of acidic species. The stoichiometry of the reaction of stone with hydrogen ion is difficult to define from the field data due to scatter in the data attributed to hydrodynamic effects. Laboratory run-off experiments show that the stoichiometry is best defined by a reaction with H+ in which CO2 is released from the system. The baseline effect caused by water in equilibrium with atmospheric CO2 is identical in the field and in laboratory simulation. The experiments show that the solutions are close enough to equilibrium for the incremental effect of hydrogen ion to be minor (i.e., 24% for marble for a rain of pH 4.0) relative to dissolution due to water and carbonic acid reactions. Stone erosion rates based on physical measurement are approximately double the recession rates that are due to dissolution (estimated from the observed calcium content of the run-off solutions). The difference may reflect the loss of granular material not included in recession estimates based on the run-off data. Neither the field nor the laboratory run-off experiments indicate a pH dependence for the grain-removal process.

Effects of simulated rain acidified with sulfuric acid on host-parasite interactions

Science.gov (United States)

D. S. Shriner

1976-01-01

Wind-blown rain, rain splash, and films of free moisture play important roles in the epidemiology of many plant diseases. The effects of simulated rain acidified with sulfuric acid were studied on several host-parasite systems. Plants were exposed, in greenhouse or field, to simulated rain of pH 3.2 ? 0.1 or pH 6.0 ? 0.2. Simulated "rain" of pH 3.2 resulted...

Moessbauer study of corrosion induced by acid rain

International Nuclear Information System (INIS)

Arshed, M.; Hussain, N.; Siddiqui, M.; Anwar-ul-Islam, M.; Rehman, S.; Butt, N.M.

1997-01-01

Strictly speaking acid rain refers to wet precipitation of pollutants S0/sub 2/SO/sub 3/ and NO/sub x/HNO/sub 3/ which have dissolved in cloud and rain droplets to from sulphuric and nitric acids. Acid rain has seriously damaged pine and spruce forests in Canada, USA and Europe. In these areas it has caused damage to buildings, reduced fish population due to acidification of lakes and rivers, and affected health of human beings as a result of poor water quality. The corrosion products formed in a simulated acid rain environment have been identified with transmission Moessbauer spectroscopy using a /sup 57/Co source. They were found to be gamma-FeOOH, alpha-FeOOH, gamma-Fe/sub 2/O/sub 3/ and a phase with unfamiliar parameters which seems to be amorphous in nature and can be considered as an intermediate phase. (author)

ARIS: Acid Rain Information System. Final project report

Energy Technology Data Exchange (ETDEWEB)

McWilliams, P.; Musante, L.

1982-04-20

ARIS is to provide the technical, government, and business communities with abstracted information from the world's significant technical and business literature. The subject areas covered by this acid rain data base includes (1) the mechanism of the formation of acid rain; (2) its transport phenomena; (3) its effects on materials; (4) its effects on plants; (5) the health effects of acid rain; and (6) monitoring and analysis of acid rain. Data in ARIS comes from several government and commercial data base producers, and these include EDB DOE Energy Database, Environmental Science Index, Air Pollution Abstracts, National Technical Service (NTIS), and articles of regional interests from various newspapers. The types of publication source documents are: technical journals, conference proceedings, selected monographs, government reports, special studies, and newspapers. The file data is proposed to be updated quarterly and will cover selected references from 1970 with major focus on material after 1976.

Characterization of rain heights due to 0° isotherm in tropical and subtropical climates: implication on rain-induced attenuation prediction

Science.gov (United States)

Ojo, J. S.; Owolawi, P. A.

2018-01-01

In this paper, the dynamics of the structure of the rain profile as related to the zero-degree isotherm height and the implications for attenuation prediction along the Earth-space propagation links at locations in Nigeria, a tropical region, and South Africa, a subtropical region, are presented. Five-year (January 2010-December 2014) precipitation data on board the Tropical Rainfall Measuring Mission (TRMM) satellite have been analyzed over some selected locations in the two regions. The influences of the zero-degree isotherm height on some observed weather parameters are also discussed. The result on the influence of air temperature on rain height h r shows a significant increase in the tropical environment as compared with those in the subtropics. However, when h r results are compared with those obtained using rain height as recommended by the International Telecommunication Union (ITU), there is a significant difference at the 0.01% unavailability of the signal in a year particularly at higher frequencies. Further comparison with the slant path attenuation at 0.01% unavailability of the signal in a year shows a slight deviation (between 1.04 and 2.13 dB) in rain height than those acquired using the measured rain height in the tropical locations. Nevertheless, the result is slightly less than those obtained using the measured rain height in the subtropical locations with the differences in dB between - 0.49 and - 1.18. The overall results will be useful for estimating the link budgeting for digital radio satellite broadcasting. It will also be applicable for radar propagation systems at higher-frequency bands in Nigeria and South Africa.

Acid Rain and Snow in Kashiwazaki City.

OpenAIRE

小野寺, 正幸; 富永, 禎秀; 竹園, 恵; 大金, 一二; Onodera, Masayuki; Tominaga, Yoshihide; Takesono, Satoshi; Oogane, Katsuji

2002-01-01

This paper described the actual condition of acid rain and snow and their influence of a winter monsoon in Kashiwazaki city. For 7 months from September in 2001 to March in 2002, the pH value was measured in rain or snow. The minimum of pH value observed was 3.9 for the 7 months. The day which observed pH

An international research program on acid rain and emissions in Asia

International Nuclear Information System (INIS)

Foell, W.K.

1992-01-01

Strong economic and population growth will accelerate the rapid development of fossil fuel energy systems throughout Asia. If the present trends continue, by early next century Asian emissions of SO 2 will exceed the present emission levels in North America and Europe combined. In response to the concern that these emissions have the potential to cause significant damage in Asia, a group of international specialists has established a project on Acid Rain and Emissions in Asia. In the initial phase of this project, work is underway to develop an integrated assessment model to assist policy makers in evaluating options to reduce precursor emissions and to catalyze the process of international policy dialogue on acid rain in Asia. 8 refs., 3 figs., 1 tab

Propagating Characteristics of Pulsed Laser in Rain

Directory of Open Access Journals (Sweden)

Jing Guo

2015-01-01

Full Text Available To understand the performance of laser ranging system under the rain weather condition, we need to know the propagating characteristics of laser pulse in rain. In this paper, the absorption and attenuation coefficients were calculated based on the scattering theories in discrete stochastic media, and the propagating characteristics of laser pulse in rain were simulated and analyzed using Monte-Carlo method. Some simulation results were verified by experiments, and the simulation results are well matched with the experimental data, with the maximal deviation not less than 7.5%. The results indicated that the propagating laser beam would be attenuated and distorted due to the scattering and absorption of raindrops, and the energy attenuation and pulse shape distortion strongly depended on the laser pulse widths.

Raine syndrome: expanding the radiological spectrum

Energy Technology Data Exchange (ETDEWEB)

Koob, Meriam; Dietemann, Jean-Louis [CHU de Strasbourg Hopital de Hautepierre, Service de Radiologie 2, Strasbourg (France); Doray, Berenice; Fradin, Melanie [CHU de Strasbourg, Hopital de Hautepierre, Laboratoire de Genetique Medicale, Strasbourg (France); Astruc, Dominique [CHU de Strasbourg Hopital de Hautepierre, Service de Neonatologie, Strasbourg (France)

2011-03-15

We describe ante- and postnatal imaging of a 1-year-old otherwise healthy girl with Raine syndrome. She presented with neonatal respiratory distress related to a pyriform aperture stenosis, which was diagnosed on CT. Signs of chondrodysplasia punctata, sagittal vertebral clefting and intervertebral disc and renal calcifications were also found on imaging. This new case confirms that Raine syndrome is not always lethal. The overlapping imaging signs with chondrodysplasia punctata and the disseminated calcifications give new insights into its pathophysiology. (orig.)

Raine syndrome: expanding the radiological spectrum

International Nuclear Information System (INIS)

Koob, Meriam; Dietemann, Jean-Louis; Doray, Berenice; Fradin, Melanie; Astruc, Dominique

2011-01-01

We describe ante- and postnatal imaging of a 1-year-old otherwise healthy girl with Raine syndrome. She presented with neonatal respiratory distress related to a pyriform aperture stenosis, which was diagnosed on CT. Signs of chondrodysplasia punctata, sagittal vertebral clefting and intervertebral disc and renal calcifications were also found on imaging. This new case confirms that Raine syndrome is not always lethal. The overlapping imaging signs with chondrodysplasia punctata and the disseminated calcifications give new insights into its pathophysiology. (orig.)

Millimeter wave propagation modeling of inhomogeneous rain media for satellite communications systems

Science.gov (United States)

Persinger, R. R.; Stutzman, W. L.

1978-01-01

A theoretical propagation model that represents the scattering properties of an inhomogeneous rain often found on a satellite communications link is presented. The model includes the scattering effects of an arbitrary distribution of particle type (rain or ice), particle shape, particle size, and particle orientation within a given rain cell. An associated rain propagation prediction program predicts attenuation, isolation and phase shift as a function of ground rain rate. A frequency independent synthetic storm algorithm is presented that models nonuniform rain rates present on a satellite link. Antenna effects are included along with a discussion of rain reciprocity. The model is verified using the latest available multiple frequency data from the CTS and COMSTAR satellites. The data covers a wide range of frequencies, elevation angles, and ground site locations.

Characteristic, origin, prediction of acid rain at Chongqing in China

International Nuclear Information System (INIS)

Xu Xiaolei; Ogura, Norio

1992-01-01

The characteristics of the acid rain at Chongqing city, Sichuan Province, China is presented. The chemical analysis of the rainwater in major cities in China, seasonal variation of pH of the rain in last decade, concentration of the SO 2 in atmosphere and in rain at Chongqing city are reviewed. The possible factors affecting the acidity is analyzed. The closed geography is revealed to be one of the cause. Industries exhausting soot and Chongqing coal thermal plant combusting coal of high sulfur and high ash concentration are the main sources of pollutants. SO 2 from coal as domestic fuel may not be ignored. It is estimated that the concentrations of SO 2 in atmosphere, SO 4 2- in rain, H + in rain, and wet precipitation shall be 0.61 mg/m 3 , 402.2μeq/l, 122.2μeq/l and 3.67mg/m 2 ·yr, respectively. Warning is made that unless rapid countermeasure shall be devised, Chongqing may become one of the worst acid rain districts. (Y.A.)

Microbial populations in an agronomically managed mollisol treated with simulated acid rain

International Nuclear Information System (INIS)

Miller, K.W.; Cole, M.A.; Banwart, W.L.

1991-01-01

A fertile well-buffered mollisol (Flanagan silt loam, fine montmorillonitic mesic Aquic Arguidoll) under cultivation with corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] was subjected to simulated rain of pH 5.6, 4.2, and 3.0, while moisture-activated rain exclusion shelters provided protection from ambient rain. Soil was sampled to a depth of 3 cm on four dates throughout the 1985 growing season. The following microorganisms were enumerated by plate counts or most probable number: general heterotrophic bacteria, general soil fungi, free-living N-fixing bacteria, fluorescent pseudomonads, autotrophic ammonium-oxidizing, nitrite-oxidizing, and thio-sulfate-oxidizing bacteria. The ANOVA was used to determine the combined and individual effects of rain treatments, crop field, and sampling date. Crop field and sampling date affected microbial numbers more than rain treatments. Overall, rain treatment effects were limited to nitrite-oxidizing bacteria; lower numbers occurred in the corn field in subplots treated with rain of pH 4.2 and 3.0, and in the soybean field treated with rain of pH 3.0. The trend was strongest in June and July. In the corn field in subplots treated with rain of pH 3.0, numbers of thiosulfate-oxidizing bacteria were higher an numbers of general heterotrophic bacteria were lower; however, these trends were comparatively weak. Rain treatments caused essentially no decrease in soil pH, suggesting that acid rain constituents affect certain microbial populations without causing overt changes in pH. Because they appear to be unusually sensitive, nitrite-oxidizing bacteria could be used as experimental indicators of changes in soil microbial communities subjected to acid rain

Evolution of drop size distribution in natural rain

Science.gov (United States)

D'Adderio, Leo Pio; Porcù, Federico; Tokay, Ali

2018-02-01

Both numerical modeling and laboratory experiments document the possibility of a raindrop size distribution (DSD) to evolve to an equilibrium stage (EDSD), where all the principal processes occur at steady rates. The aim of this work is to observe the temporal behavior of the DSD and to directly investigate the conditions favorable to the onset of the EDSD in natural rain. We exploited a large disdrometer dataset collected in the framework of the Ground Validation activities related to the NASA Global Precipitation Measurement mission. More than 200,000 one-minute data of two-dimensional video disdrometer (2DVD) are collected over USA to represent a wide range of precipitation types. The original data are averaged over 2 min and an automatic algorithm is used on a selected subset to identify samples with EDSD. Results show that the EDSD occurs mainly in convective events and lasts for very short time intervals (2 to 4 min). It is more frequent for rain rate between 20 and 40 mm h- 1 and it mostly occurs during sharp increase of precipitation rates.

Hurricane Imaging Radiometer Wind Speed and Rain Rate Retrievals during the 2010 GRIP Flight Experiment

Science.gov (United States)

Sahawneh, Saleem; Farrar, Spencer; Johnson, James; Jones, W. Linwood; Roberts, Jason; Biswas, Sayak; Cecil, Daniel

2014-01-01

Microwave remote sensing observations of hurricanes, from NOAA and USAF hurricane surveillance aircraft, provide vital data for hurricane research and operations, for forecasting the intensity and track of tropical storms. The current operational standard for hurricane wind speed and rain rate measurements is the Stepped Frequency Microwave Radiometer (SFMR), which is a nadir viewing passive microwave airborne remote sensor. The Hurricane Imaging Radiometer, HIRAD, will extend the nadir viewing SFMR capability to provide wide swath images of wind speed and rain rate, while flying on a high altitude aircraft. HIRAD was first flown in the Genesis and Rapid Intensification Processes, GRIP, NASA hurricane field experiment in 2010. This paper reports on geophysical retrieval results and provides hurricane images from GRIP flights. An overview of the HIRAD instrument and the radiative transfer theory based, wind speed/rain rate retrieval algorithm is included. Results are presented for hurricane wind speed and rain rate for Earl and Karl, with comparison to collocated SFMR retrievals and WP3D Fuselage Radar images for validation purposes.

The regional costs and benefits of acid rain control

International Nuclear Information System (INIS)

Berkman, M.P.

1991-01-01

Congress recently enacted acid rain control legislation as part of the 1990 Clean Air Act Amendments following a decade-long debate among disparate regional interests. Although Congress succeeded in drafting a law acceptable to all regions, the regional costs and benefits of the legislation remain uncertain. The research presented here attempts to estimate the regional costs and benefits and the economic impacts of acid rain controls. These estimates are made using a modeling system composed of econometric, linear programming and input-output models. The econometric and linear programming components describe markets for electricity and coal. The outputs of these components including capital investment, electricity demand, and coal production are taken as exogenous inputs by a multiregional input-output model. The input-output model produces estimates of changes in final demand, gross output, and employment. The utility linear programming model also predicts sulfur dioxide emissions (an acid-rain precursor). According to model simulations, the costs of acid rain control exceed the benefits for many regions including several regions customarily thought to be the major beneficiaries of acid rain control such as New England

Quality control of rain data used for urban runoff systems

DEFF Research Database (Denmark)

Jørgensen, H. K.; Rosenørn, S.; Madsen, Henrik

1998-01-01

for collection and quality control of rain data from a network of tipping bucket rain gauges in Denmark carried out by the Danish Meteorological Institute. During rain, the RIMCO gauge counts the number of tips teach of 0.2 mm of precipitation) every minute, The quality control of the rain data includes...... an automatic and a manual bit marking, where the automatic control basically is pointing out minutes with extreme intensities. In the manual control, the maximum intensities as well as the daily totals of precipitation are inspected, using weather charts, intensity plots and precipitation sums of nearby...

Uses of warmed water in agriculture. Final report

International Nuclear Information System (INIS)

Garrett, R.E.

1978-11-01

Energy in the form of warmed water is available from condenser cooling water from fossil fuel or nuclear-electric power-generating facilities, geothermal power plants, geothermal fluids, or spent steam and cooling water from industrial processes. A re-analysis of the characteristics of possible agricultural uses of warmed water has revealed the need to decouple considerations of warmed water sources from those of warmed water users. Conflicting objectives and managerial requirements seem to preclude an integrated system approach. Rather an interface must be established with separate costs and benefits identified for a reliable warmed water source and for its various potential uses. These costs and benefits can be utilized as a basis for decisions separately by the energy supplier and the prospective energy users. A method of classifying uses of warmed water according to need, volume, objective, temperature, and quality is presented and preliminary classifications are discussed for several potential agricultural uses of warmed water. Specific uses for soil warming, space heating in greenhouses, and irrigation are noted. Specific uses in aquaculture for catfish, lobster, and prawn production are discussed. Warmed water use in animal shelters is mentioned. Low-quality heat is required for methane generation from biomass and warmed water heating could be utilized in this industry. 53 references

Mechanics of interrill erosion with wind-driven rain

Science.gov (United States)

The vector physics of wind-driven rain (WDR) differs from that of wind-free rain, and the interrill soil detachment equations in the Water Erosion Prediction Project (WEPP) model were not originally developed to deal with this phenomenon. This article provides an evaluation of the performance of the...

Amplified Arctic warming by phytoplankton under greenhouse warming.

Science.gov (United States)

Park, Jong-Yeon; Kug, Jong-Seong; Bader, Jürgen; Rolph, Rebecca; Kwon, Minho

2015-05-12

Phytoplankton have attracted increasing attention in climate science due to their impacts on climate systems. A new generation of climate models can now provide estimates of future climate change, considering the biological feedbacks through the development of the coupled physical-ecosystem model. Here we present the geophysical impact of phytoplankton, which is often overlooked in future climate projections. A suite of future warming experiments using a fully coupled ocean-atmosphere model that interacts with a marine ecosystem model reveals that the future phytoplankton change influenced by greenhouse warming can amplify Arctic surface warming considerably. The warming-induced sea ice melting and the corresponding increase in shortwave radiation penetrating into the ocean both result in a longer phytoplankton growing season in the Arctic. In turn, the increase in Arctic phytoplankton warms the ocean surface layer through direct biological heating, triggering additional positive feedbacks in the Arctic, and consequently intensifying the Arctic warming further. Our results establish the presence of marine phytoplankton as an important potential driver of the future Arctic climate changes.

Rain Characteristics and Large-Scale Environments of Precipitation Objects with Extreme Rain Volumes from TRMM Observations

Science.gov (United States)

Zhou, Yaping; Lau, William K M.; Liu, Chuntao

2013-01-01

This study adopts a "precipitation object" approach by using 14 years of Tropical Rainfall Measuring Mission (TRMM) Precipitation Feature (PF) and National Centers for Environmental Prediction (NCEP) reanalysis data to study rainfall structure and environmental factors associated with extreme heavy rain events. Characteristics of instantaneous extreme volumetric PFs are examined and compared to those of intermediate and small systems. It is found that instantaneous PFs exhibit a much wider scale range compared to the daily gridded precipitation accumulation range. The top 1% of the rainiest PFs contribute over 55% of total rainfall and have 2 orders of rain volume magnitude greater than those of the median PFs. We find a threshold near the top 10% beyond which the PFs grow exponentially into larger, deeper, and colder rain systems. NCEP reanalyses show that midlevel relative humidity and total precipitable water increase steadily with increasingly larger PFs, along with a rapid increase of 500 hPa upward vertical velocity beyond the top 10%. This provides the necessary moisture convergence to amplify and sustain the extreme events. The rapid increase in vertical motion is associated with the release of convective available potential energy (CAPE) in mature systems, as is evident in the increase in CAPE of PFs up to 10% and the subsequent dropoff. The study illustrates distinct stages in the development of an extreme rainfall event including: (1) a systematic buildup in large-scale temperature and moisture, (2) a rapid change in rain structure, (3) explosive growth of the PF size, and (4) a release of CAPE before the demise of the event.

Agro-climatic Methodology of rain distribution

International Nuclear Information System (INIS)

Lasso Espinosa, Luis D.

2003-01-01

Rain distribution is almost, the most important impute on agricultural activities in any place in Colombia. The method to define when rain is well or bad distributed follows the next criteria: one effective rainy day or day with sufficient amount of water for crop development is one, in which, the amount of precipitation is between 0.5 ETP and 3 ETP. On the other hand, one dray day has rain less than 0.5 ETP and one humid day one with more than 3 ETP. Which that in main, it's possible to considered a very well distributed month for agricultural practices, one who has more effective rainy days than dray or humid days or intermittent effective, humid and dray days. In this exercise was used the daily precipitation data for 1969 -1997 period of Tangua meteorological station, located at 01 degrade 05 minutes 50 seconds N latitude and 77 degrade 23 minutes 53 seconds W longitude, and 2400 meters over the sea level. The results show October and November as the only months of the year, with one humid month, each one, during the whole period, that means 3 % of the cases and July, august and September as the driest epoch. On the other hand, months with suitable rain for agricultural activities are, January with 21 % of the cases, February 45%, march 38 %, April 55 %, may 28 %, June 7 %, October 28 %, November 48 % and December with 34 % of the cases

Initiation of Recent Debris Flows on Mount Rainier, Washington: A Climate Warming Signal?

Science.gov (United States)

Copeland, E. A.; Kennard, P.; Nolin, A. W.; Lancaster, S. T.; Grant, G. E.

2008-12-01

The first week of November 2006 an intense rainstorm inundated the Pacific Northwest and triggered debris flows on many large volcanoes in the Cascade Range of Washington and Oregon. At Mount Rainier, Washington, 45.7 cm of rain was recorded in 36 hours; the storm was preceded by a week of light precipitation and moderate temperatures, so that rain fell on nearly-saturated ground with minimal snow cover. The November 2006 storm was exceptional in that it resulted in a 100-year flood and caused an unprecedented six-month closure of Mount Rainier National Park. It also focused inquiry as to whether debris flows from Cascade volcanoes are likely to occur more frequently in the future as glaciers recede due to climate warming, leaving unstable moraines and sediment that can act as initiation sites. We examined the recent history of debris flows from Mount Rainier using aerial photographs and field surveyed debris flow tracks. Prior to 2001, debris flows were recorded in association with rainfall or glacial outburst floods in 4 drainages, but 3 additional drainages were first impacted by debris flows in 2001, 2005, and 2006, respectively. We discovered that most of the recent debris flows initiated as small gullies in unconsolidated material at the edge of fragmented glaciers or areas of permanent snow and ice. Other initiation sites occur on steep-sided un-vegetated moraines. Of the 28 named glaciers on Mount Rainier, debris flows initiated near five glaciers in the exceptional storm of 2006 (Winthrop, Inter, Kautz-Success, Van Trump, Pyramid, and South Tahoma). Less exceptional storms, however, have also produced wide-spread debris flows: in September 2005, 15.3 cm of rain fell in 48 hours on minimal snow cover and caused debris flows in all except 2 of the glacier drainages that initiated in 2006. Debris flows from both storms initiated at elevations of 1980 to 2400 m, traveled 5 to 10 kilometers, and caused significant streambed aggradation. These results suggest a

Acid Rain, pH & Acidity: A Common Misinterpretation.

Science.gov (United States)

Clark, David B.; Thompson, Ronald E.

1989-01-01

Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

Relativistically speaking: Let's walk or run through the rain?

OpenAIRE

Assis, Armando V. D. B.

2010-01-01

We analyse under a simple approach the problem one must decide the best strategy to minimize the contact with rain when moving between two points through the rain. The available strategies: walk (low speed boost $

On validation of the rain climatic zone designations for Nigeria

Science.gov (United States)

Obiyemi, O. O.; Ibiyemi, T. S.; Ojo, J. S.

2017-07-01

In this paper, validation of rain climatic zone classifications for Nigeria is presented based on global radio-climatic models by the International Telecommunication Union-Radiocommunication (ITU-R) and Crane. Rain rate estimates deduced from several ground-based measurements and those earlier estimated from the precipitation index on the Tropical Rain Measurement Mission (TRMM) were employed for the validation exercise. Although earlier classifications indicated that Nigeria falls into zones P, Q, N, and K for the ITU-R designations, and zones E and H for Crane's climatic zone designations, the results however confirmed that the rain climatic zones across Nigeria can only be classified into four, namely P, Q, M, and N for the ITU-R designations, while the designations by Crane exhibited only three zones, namely E, G, and H. The ITU-R classification was found to be more suitable for planning microwave and millimeter wave links across Nigeria. The research outcomes are vital in boosting the confidence level of system designers in using the ITU-R designations as presented in the map developed for the rain zone designations for estimating the attenuation induced by rain along satellite and terrestrial microwave links over Nigeria.

Endangerment of cultural heritage sites by strong rain

Science.gov (United States)

Krauß, Thomas; Fischer, Peter

2017-09-01

Due to climate change extreme weather conditions become more and more frequent in the last years. Especially in Germany nearly every year a large flood event happens. Most of these events are caused by strong rain. There are at most two causes for these floodings: The first is locally strong rain in the area of damage, the second happens at damage sites located near confluxes and strong rain in the upper stream areas of the joining rivers. The amount of damage is often strongly correlated with unreasonable designation of new construction in such endangered regions. Our presented study is based on an earlier project together with a German insurance company. In this project we analyzed correlations of geographical settings with the insurance data of flood damages over ten years. The result of this study was a strong relation of the terrain with the amount and the probability of damages. Further investigations allow us to derive a system for estimating potential endangerment due to strong rain just from suitable digital terrain models (DTMs). In the presented study we apply this method to different types of cultural heritage (CH) sites in Germany and other parts of the world to detect which type of CH sites were build with potential endangerment of strong rain events in mind and which ones are prone to such events.

Construction of Polarimetric Radar-Based Reference Rain Maps for the Iowa Flood Studies Campaign

Science.gov (United States)

Petersen, Walt; Krajewski, Witek; Wolff, David; Gatlin, Patrick

2015-04-01

The Global Precipitation Measurement (GPM) Mission Iowa Flood Studies (IFloodS) campaign was conducted in central and northeastern Iowa during the months of April-June, 2013. Specific science objectives for IFloodS included quantification of uncertainties in satellite and ground-based estimates of precipitation, 4-D characterization of precipitation physical processes and associated parameters (e.g., size distributions, water contents, types, structure etc.), assessment of the impact of precipitation estimation uncertainty and physical processes on hydrologic predictive skill, and refinement of field observations and data analysis approaches as they pertain to future GPM integrated hydrologic validation and related field studies. In addition to field campaign archival of raw and processed satellite data (including precipitation products), key ground-based platforms such as the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms, and a large network of 2D Video and Parsivel disdrometers were deployed. In something of a canonical approach, the radar (NPOL in particular), gauge and disdrometer observational assets were deployed to create a consistent high-quality distributed (time and space sampling) radar-based ground "reference" rainfall dataset, with known uncertainties, that could be used for assessing the satellite-based precipitation products at a range of space/time scales. Subsequently, the impact of uncertainties in the satellite products could be evaluated relative to the ground-benchmark in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction. Relative to establishing the ground-based "benchmark", numerous avenues were pursued in the making and verification of IFloodS "reference" dual-polarimetric radar-based rain maps, and this study documents the process and results as they pertain specifically

Construction of Polarimetric Radar-Based Reference Rain Maps for the Iowa Flood Studies Campaign

Science.gov (United States)

Petersen, Walter; Wolff, David; Krajewski, Witek; Gatlin, Patrick

2015-01-01

The Global Precipitation Measurement (GPM) Mission Iowa Flood Studies (IFloodS) campaign was conducted in central and northeastern Iowa during the months of April-June, 2013. Specific science objectives for IFloodS included quantification of uncertainties in satellite and ground-based estimates of precipitation, 4-D characterization of precipitation physical processes and associated parameters (e.g., size distributions, water contents, types, structure etc.), assessment of the impact of precipitation estimation uncertainty and physical processes on hydrologic predictive skill, and refinement of field observations and data analysis approaches as they pertain to future GPM integrated hydrologic validation and related field studies. In addition to field campaign archival of raw and processed satellite data (including precipitation products), key ground-based platforms such as the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms, and a large network of 2D Video and Parsivel disdrometers were deployed. In something of a canonical approach, the radar (NPOL in particular), gauge and disdrometer observational assets were deployed to create a consistent high-quality distributed (time and space sampling) radar-based ground "reference" rainfall dataset, with known uncertainties, that could be used for assessing the satellite-based precipitation products at a range of space/time scales. Subsequently, the impact of uncertainties in the satellite products could be evaluated relative to the ground-benchmark in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction. Relative to establishing the ground-based "benchmark", numerous avenues were pursued in the making and verification of IFloodS "reference" dual-polarimetric radar-based rain maps, and this study documents the process and results as they pertain specifically

Estimating the exceedance probability of rain rate by logistic regression

Science.gov (United States)

Chiu, Long S.; Kedem, Benjamin

1990-01-01

Recent studies have shown that the fraction of an area with rain intensity above a fixed threshold is highly correlated with the area-averaged rain rate. To estimate the fractional rainy area, a logistic regression model, which estimates the conditional probability that rain rate over an area exceeds a fixed threshold given the values of related covariates, is developed. The problem of dependency in the data in the estimation procedure is bypassed by the method of partial likelihood. Analyses of simulated scanning multichannel microwave radiometer and observed electrically scanning microwave radiometer data during the Global Atlantic Tropical Experiment period show that the use of logistic regression in pixel classification is superior to multiple regression in predicting whether rain rate at each pixel exceeds a given threshold, even in the presence of noisy data. The potential of the logistic regression technique in satellite rain rate estimation is discussed.

Effects and mechanism of acid rain on plant chloroplast ATP synthase.

Science.gov (United States)

Sun, Jingwen; Hu, Huiqing; Li, Yueli; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

2016-09-01

Acid rain can directly or indirectly affect plant physiological functions, especially photosynthesis. The enzyme ATP synthase is the key in photosynthetic energy conversion, and thus, it affects plant photosynthesis. To clarify the mechanism by which acid rain affects photosynthesis, we studied the effects of acid rain on plant growth, photosynthesis, chloroplast ATP synthase activity and gene expression, chloroplast ultrastructure, intracellular H(+) level, and water content of rice seedlings. Acid rain at pH 4.5 remained the chloroplast structure unchanged but increased the expression of six chloroplast ATP synthase subunits, promoted chloroplast ATP synthase activity, and increased photosynthesis and plant growth. Acid rain at pH 4.0 or less decreased leaf water content, destroyed chloroplast structure, inhibited the expression of six chloroplast ATP synthase subunits, decreased chloroplast ATP synthase activity, and reduced photosynthesis and plant growth. In conclusion, acid rain affected the chloroplast ultrastructure, chloroplast ATPase transcription and activity, and P n by changing the acidity in the cells, and thus influencing the plant growth and development. Finally, the effects of simulated acid rain on the test indices were found to be dose-dependent.

Rain Forests: Do They Hold Up the Sky?

Science.gov (United States)

Shaw, Donna Gail; Dybdahl, Claudia S.

1992-01-01

This paper uses the topic of rain forests to demonstrate how a meaningful and relevant Science, Technology, and Society program can be designed for intermediate-level students. Students create and immerse themselves in a tropical rain forest, explore the forest ecosystem and peoples, and consider solutions to the problem of deforestation. (JDD)

"Lacking warmth": Alexithymia trait is related to warm-specific thermal somatosensory processing.

Science.gov (United States)

Borhani, Khatereh; Làdavas, Elisabetta; Fotopoulou, Aikaterini; Haggard, Patrick

2017-09-01

Alexithymia is a personality trait involving deficits in emotional processing. The personality construct has been extensively validated, but the underlying neural and physiological systems remain controversial. One theory suggests that low-level somatosensory mechanisms act as somatic markers of emotion, underpinning cognitive and affective impairments in alexithymia. In two separate samples (total N=100), we used an established Quantitative Sensory Testing (QST) battery to probe multiple neurophysiological submodalities of somatosensation, and investigated their associations with the widely-used Toronto Alexithymia Scale (TAS-20). Experiment one found reduced sensitivity to warmth in people with higher alexithymia scores, compared to individuals with lower scores, without deficits in other somatosensory submodalities. Experiment two replicated this result in a new group of participants using a full-sample correlation between threshold for warm detection and TAS-20 scores. We discuss the relations between low-level thermoceptive function and cognitive processing of emotion. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Combined acid rain and lanthanum pollution and its potential ecological risk for nitrogen assimilation in soybean seedling roots.

Science.gov (United States)

Zhang, Fan; Cheng, Mengzhu; Sun, Zhaoguo; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

2017-12-01

Rare earth elements (REEs) are used in various fields, resulting in their accumulation in the environment. This accumulation has affected the survival and distribution of crops in various ways. Acid rain is a serious global environmental problem. The combined effects on crops from these two types of pollution have been reported, but the effects on crop root nitrogen assimilation are rarely known. To explore the impact of combined contamination from these two pollutants on crop nitrogen assimilation, the soybean seedlings were treated with simulated environmental pollution from acid rain and a representative rare earth ion, lanthanum ion (La 3+ ), then the indexes related to plant nitrogen assimilation process in roots were determined. The results showed that combined treatment with pH 4.5 acid rain and 0.08 mM La 3+ promoted nitrogen assimilation synergistically, while the other combined treatments all showed inhibitory effects. Moreover, acid rain aggravated the inhibitory effect of 1.20 or 0.40 mM La 3+ on nitrogen assimilation in soybean seedling roots. Thus, the effects of acid rain and La 3+ on crops depended on the combination levels of acid rain intensity and La 3+ concentration. Acid rain increases the bioavailability of La 3+ , and the combined effects of these two pollutants were more serious than that of either pollutant alone. These results provide new evidence in favor of limiting overuse of REEs in agriculture. This work also provides a new framework for ecological risk assessment of combined acid rain and REEs pollution on soybean crops. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measurement of rain intensity by means of active-passive remote sensing

Science.gov (United States)

Linkova, Anna; Khlopov, Grygoriy

2014-05-01

Measurement of rain intensity is of great interest for municipal services and agriculture, particularly because of increasing number of floods and landslides. At that monitoring of amount of liquid precipitation allows to schedule work of hydrological services to inform the relevant public authorities about violent weather in time. That is why development of remote sensing methods for monitoring of rains is quite important task. The inverse problem solution of rain remote sensing is based on the measurements of scattering or radiation characteristics of rain drops. However liquid precipitation has a difficult structure which depends on many parameters. So using only scattering or radiation characteristics obtained by active and passive sensing at a single frequency does not allow to solve the inverse problem. Therefore double frequency sensing is widely used now for precipitation monitoring. Measurement of reflected power at two frequencies allows to find two parameters of drop size distribution of rain drops. However three-parameter distributions (for example gamma distribution) are the most prevalent now as a rain model, so in this case solution of the inverse problem requires the measurement of at least three uncorrelated variables. That is why a priori statistical meteorological data obtained by contact methods are used additionally to the double frequency sensing to solve the inverse problem. In particular, authors proposed and studied the combined method of double frequency sensing of rains based on dependence of the parameters of gamma distribution on rain intensity. The numerical simulation and experimental study shown that the proposed method allows to retrieve the profile of microstructure and integral parameters of rain with accuracy less than 15%. However, the effectiveness of the proposed method essentially depends on the reliability of the used statistical data which are tend to have a strong seasonal and regional variability led to significant

Lightning-based propagation of convective rain fields

Directory of Open Access Journals (Sweden)

S. Dietrich

2011-05-01

Full Text Available This paper describes a new multi-sensor approach for continuously monitoring convective rain cells. It exploits lightning data from surface networks to propagate rain fields estimated from multi-frequency brightness temperature measurements taken by the AMSU/MHS microwave radiometers onboard NOAA/EUMETSAT low Earth orbiting operational satellites. Specifically, the method allows inferring the development (movement, morphology and intensity of convective rain cells from the spatial and temporal distribution of lightning strokes following any observation by a satellite-borne microwave radiometer. Obviously, this is particularly attractive for real-time operational purposes, due to the sporadic nature of the low Earth orbiting satellite measurements and the continuous availability of ground-based lightning measurements – as is the case in most of the Mediterranean region. A preliminary assessment of the lightning-based rainfall propagation algorithm has been successfully made by using two pairs of consecutive AMSU observations, in conjunction with lightning measurements from the ZEUS network, for two convective events. Specifically, we show that the evolving rain fields, which are estimated by applying the algorithm to the satellite-based rainfall estimates for the first AMSU overpass, show an overall agreement with the satellite-based rainfall estimates for the second AMSU overpass.

Daytime warming has stronger negative effects on soil nematodes than night-time warming

OpenAIRE

Yan, Xiumin; Wang, Kehong; Song, Lihong; Wang, Xuefeng; Wu, Donghui

2017-01-01

Warming of the climate system is unequivocal, that is, stronger warming during night-time than during daytime. Here we focus on how soil nematodes respond to the current asymmetric warming. A field infrared heating experiment was performed in the western of the Songnen Plain, Northeast China. Three warming modes, i.e. daytime warming, night-time warming and diurnal warming, were taken to perform the asymmetric warming condition. Our results showed that the daytime and diurnal warming treatmen...

Rain Erosion/Measurement Impact Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The FARM Rain Erosion/Impact Measurement Lab develops solutions for deficiencies in the ability of materials, coatings and designs to withstand a severe operational...

Economic restructuring in Eastern Europe and acid rain abatement strategies

International Nuclear Information System (INIS)

Amann, Markus; Klaassen, Ger; Schoepp, Wolfgang; Soerensen, Lene; Hordijk, Leen

1992-01-01

Acid rain abatement strategies in Europe are currently being discussed in view of the expiration of the Helsinki Protocol on SO 2 emission reduction. The changing energy situation in Eastern European countries is expected to have an influence on the deposition pattern in Europe. The paper presents a consistent energy scenario for Eastern European countries and compares optimal strategies to reduce SO 2 emissions. These strategies are based on runs with the RAINS model in which environmental targets have been set based on critical loads for sulphur. The analysis shows that economic restructuring and efficiency improvements in Eastern European countries, as well as in Western Europe, may result in significantly lower sulphur abatement costs. Potential assistance to Eastern Europe to guarantee desired environmental standards in Western countries should therefore focus not only on providing emission control devices but also on the success of the economic transition process. (author)

Amount and composition of rain failing at Rothamsted

Energy Technology Data Exchange (ETDEWEB)

Russell, E J; Richards, E H

1919-01-01

The monthly fluctuations in the ammoniacal concentration varies with rainfall, i.e., highest in spring; lowest in winter. The nitric nitrogen concentration fluctuated year by year and month by month in the same way as the ammoniacal nitrogen and the rainfall until 1910, since when there has been no simple relationship. The close relationship between the amounts of ammoniacal and nitric nitrogen suggests either a common origin or the production of nitric compounds from ammonia. Chlorine fluctuations closely follow the rainfall also. Since 1888, when the experiments began, to 1916, when they terminated, there has been a rise in the amounts of nitric nitrogen and of chlorine in the rain. In the case of chlorine a parallel series of determinations made at Cirencester over the same period shows a similar rise. There is no rise of ammonia but on the contrary a tendency to drop; the sum of ammoniacal and nitric nitrogen shows little change over the period. This seems to suggest that a former source of ammonia is now turning out nitric acid. It is possible that modern gas burners and grates tend to the formation of nitric oxides rather than of ammonia. Rain contains on an average 10 parts of dissolved oxygen per million, the amount being higher in winter than in summer: 66.4 lb per acre per annum was brought down during the two years over which the determinations extended. The marked difference in composition between summer and winter rainfall suggests that these may differ in their origin. The winter rain resembles Atlantic rain in its high chlorine and low ammonia and nitrate content; the summer rain is characterized by low chlorine but high ammonia and nitrate content, suggesting that it arises by evaporation of water from the soil and condensation at higher altitudes than in the case of winter rain.

Small inner companions of warm Jupiters: Lifetimes and legacies

International Nuclear Information System (INIS)

Van Laerhoven, Christa; Greenberg, Richard

2013-01-01

Although warm Jupiters are generally too far from their stars for tides to be important, the presence of an inner planetary companion to a warm Jupiter can result in tidal evolution of the system. Insight into the process and its effects comes form classical secular theory of planetary perturbations. The lifetime of the inner planet may be shorter than the age of the system, because the warm Jupiter maintains its eccentricity and hence promotes tidal migration into the star. Thus a warm Jupiter observed to be alone in its system might have previously cleared away any interior planets. Before its demise, even if an inner planet is of terrestrial scale, it may promote damping of the warm Jupiter's eccentricity. Thus any inferences of the initial orbit of an observed warm Jupiter must include the possibility of a greater initial eccentricity than would be estimated by assuming it had always been alone. Tidal evolution involving multiple planets also enhances the internal heating of the planets, which readily exceeds that of stellar radiation for the inner planet, and may be great enough to affect the internal structure of warm Jupiters. Secular theory gives insight into the tidal processes, providing, among other things, a way to constrain eccentricities of transiting planets based on estimates of the tidal parameter Q.

Foliar contamination of plants with aerosols of 137Cs, 85Sr, 133Ba and 123mTe: influence of rain

International Nuclear Information System (INIS)

Madoz-Escande, C.; Bonhomme, T.; Poncet-Bonnard, D.

2004-01-01

Different types of plants (lettuce, radish and grass sward) were contaminated by dry deposition of radioactive aerosols ( 137 Cs, 85 Sr, 133 Ba and 123m Te). Due to the rain efficiency in decreasing radiological contamination of crops, a range of rain scenarios was applied on these three types of plants. These experiments aimed at improving the prediction of the consequences on agricultural products of a nuclear accident occurring on a PWR, and also at improving the understanding of the different processes occurring between the contamination and the first harvest. For a plant species at a given stage of its growth cycle, interception of the four radionuclides was identical and varied from 68% for radish to 84% for grass. The interception of aerosols by lettuce was intermediary with 75% (at the middle of ripeness stage) or 78%(at the mature plant stage). By the use of a conceptual model, the predominance between the two processes: washing-off the leaves and absorption through the leaves cuticles that allows the translocation, was evidenced. For Cs, Sr and Ba,, for the lettuce and the radish the washing-off process on the foliar cover of lettuce and radish was the most significant during the first rain. The absorption process inside the plant became dominant only from the third rain event. Tellurium had a particular behaviour: it was non-mobile and stayed put on the leaves. The values of the washing-off and absorption coefficients were estimated. For the grass, during the washing-off, radionuclides had a tendency to accumulate in the basal parts of plant first and the root matt later. Moreover, grass cuts came in between the rains. The global transfer factor values were dependant on both the radionuclides and the plant species, nevertheless the higher value was obtained for the cesium, whatever the plant and the rain (from 0,06 m 2 .kg fresh -1 for radish to 0,1 m 2 .kg fresh -1 for whole lettuce). (author)

A pair of new moisture-dynamic diagnostic parameters for heavy rain location

Science.gov (United States)

Yuan, Kai; Zhu, Zhiwei; Li, Ming

2018-06-01

In this study, the regional persistent heavy rain process occurred in the middle and lower reaches of the Yangtze River valley from 30 June 2016 to 7 July 2016 is analyzed. We find that the pure dynamic parameters [e.g., vorticity ( V) and divergence ( D)] and two-dimensional moisture-dynamic parameters [e.g., moist vorticity ( MV), moist divergence ( MD)] have difficulty in capturing the rainfall location during such a critical process. Given the poor performance of these traditional parameters, a pair of new parameters [namely, one-dimensional moist vorticity ( ODMV) and one-dimensional moist divergence ( ODMD)] based on low-level jet is proposed for diagnosing heavy rain location. The results show that (1) ODMV and ODMD have better relations with rain belt in terms of spatial distribution. Precipitation occurs in positive (negative) region of ODMV ( ODMD), and heavy rainfall accurately locates in the positive (negative) center of ODMV ( ODMD); (2) ODMV and ODMD also have good correlation with the precipitation in terms of temporal variation (significant at the 99% confidence level). When ODMV ( ODMD) is in strong positive (negative) phase, precipitation is large, and vice versa; (3) the threat score of ODMV and ODMD for the areal-mean rainfall is improved by 119% and 16%, respectively, compared to V/ D and MV/ MD. It is anticipated that the proposed new parameters would facilitate the skills of diagnosing and forecasting the heavy rainfall.

[Effects of simulated acid rain on water physiological characteristics of Myrica rubra seedlings].

Science.gov (United States)

Yaho, Zhao-bin; Jiang, Hong; Yu, Shu-quan; Lu, Mei-juan

2011-08-01

Taking the seedlings of typical subtropical economic tree species Myrica rubra in Zhejiang Province as test materials, a pot experiment was conducted to study their water physiological characteristics under effects of simulated acid rain (pH 2.5 and pH 4.0), with water (pH 5.6) as the control. Season, year, and acid rain all had significant effects on the photosynthetic rate (Pn). Among the treatments, the Pn had a greater difference in summer than in spring and autumn, and was higher in treatment acid rain (pH 4.0). Season, year, acid rain, and the interactions of season and year and of the three factors had significant effects on the stomata conductance (Gs), and also, the Gs had a greater difference among the treatments in summer than in spring and autumn. Acid rain had inhibitory effect on Gs. Season, year, acid rain, and the interactions of season and year and of season and acid rain affected the transpiration rate (Tr) significantly. Same as Pn and Gs, the Tr had a greater difference among the treatments in summer than in spring and autumn. Acid rain (pH 2.5) had the strongest inhibitory effect on Tr. Acid rain and the interactions of season and year and of season and acid rain had significant effects on the water use efficiency (WUE), and acid rain (pH 2.5) had definitely positive effect on the WUE.

Detecting Sulfuric and Nitric Acid Rain Stresses on Quercus glauca through Hyperspectral Responses.

Science.gov (United States)

Wang, Shanqian; Zhang, Xiuying; Ma, Yuandan; Li, Xinhui; Cheng, Min; Zhang, Xiaomin; Liu, Lei

2018-03-09

Acid rain, which has become one of the most severe global environmental issues, is detrimental to plant growth. However, effective methods for monitoring plant responses to acid rain stress are currently lacking. The hyperspectral technique provides a cost-effective and nondestructive way to diagnose acid rain stresses. Taking a widely distributed species ( Quercus glauca ) in Southern China as an example, this study aims to monitor the hyperspectral responses of Q. glauca to simulated sulfuric acid rain (SAR) and nitric acid rain (NAR). A total of 15 periods of leaf hyperspectral data under four pH levels of SAR and NAR were obtained during the experiment. The results showed that hyperspectral information could be used to distinguish plant responses under acid rain stress. An index (green peak area index, GPAI) was proposed to indicate acid rain stresses, based on the significantly variations in the region of 500-660 nm. Light acid rain (pH 4.5 SAR and NAR) promoted Q. glauca growth relative to the control groups (pH 5.6 SAR and NAR); moderate acid rain (pH 3.0 SAR) firstly promoted and then inhibited plant growth, while pH 3.0 NAR showed mild inhibitory effects during the experiment; and heavy acid rain (pH 2.0) significantly inhibited plant growth. Compared with NAR, SAR induced more serious damages to Q. glauca . These results could help monitor acid rain stress on plants on a regional scale using remote sensing techniques.

Projected changes over western Canada using convection-permitting regional climate model and the pseudo-global warming method

Science.gov (United States)

Li, Y.; Kurkute, S.; Chen, L.

2017-12-01

Results from the General Circulation Models (GCMs) suggest more frequent and more severe extreme rain events in a climate warmer than the present. However, current GCMs cannot accurately simulate extreme rainfall events of short duration due to their coarse model resolutions and parameterizations. This limitation makes it difficult to provide the detailed quantitative information for the development of regional adaptation and mitigation strategies. Dynamical downscaling using nested Regional Climate Models (RCMs) are able to capture key regional and local climate processes with an affordable computational cost. Recent studies have demonstrated that the downscaling of GCM results with weather-permitting mesoscale models, such as the pseudo-global warming (PGW) technique, could be a viable and economical approach of obtaining valuable climate change information on regional scales. We have conducted a regional climate 4-km Weather Research and Forecast Model (WRF) simulation with one domain covering the whole western Canada, for a historic run (2000-2015) and a 15-year future run to 2100 and beyond with the PGW forcing. The 4-km resolution allows direct use of microphysics and resolves the convection explicitly, thus providing very convincing spatial detail. With this high-resolution simulation, we are able to study the convective mechanisms, specifically the control of convections over the Prairies, the projected changes of rainfall regimes, and the shift of the convective mechanisms in a warming climate, which has never been examined before numerically at such large scale with such high resolution.

Rain rate measurements over global oceans from IRS-P4 MSMR

Indian Academy of Sciences (India)

In this paper rain estimation capability of MSMR is explored. MSMR brightness temperature data of six channels corresponding to three frequencies of 10, 18 and 21 GHz are colocated with the TRMM Microwave Imager (TMI) derived rain rates to find a new empirical algorithm for rain rate by multiple regression. Multiple ...

Neutron activation analysis of trace elements in rain water

International Nuclear Information System (INIS)

Luten, J.B.

1977-01-01

In this thesis the principles and practical aspects of activation analysis which are of direct importance in the analysis of rain water, are presented together with recent literature data on other techniques. Problems due to the storage of rain water samples are discussed. A multi-element method for the determination of trace elements in rain water by instrumental neutron activation analysis is described. Gamma ray spectrometry using Ge(Li) detectors offers the possibility to determine Na, Al, Cl, V, Mn, Co, Cu, Br and I in rain water samples of 2.5 ml after a 4-min irradiation in a thermal neutron flux of 5 x 10 13 n cm -2 s -1 . In residues of rain water samples of 100 ml, irradiated during 2 days in a thermal neutron flux of >5 x 10 13 n cm -2 s -1 Cr, Fe, Co, Zn and Sb can be determined after a cooling period of approximately 21 days. The detection limits are lower than those reported in previous investigations except for Cu. The precision is about 10% or better, except for Co, Cu and I. A routine method for the determination of bromine and iodine in rain water by n.a.a. is presented. The elements are isolated by isotope exchange between the irradiated sample and a solution of Br 2 or I 2 in CCl 4 . The method is not sensitive to the chemical species in which the halogen is present. Irradiation of solutions of iodine compounds in a high thermal neutron flux gives rise to the formation of iodate. Results of a further investigation of this phenomenon are given, as well as the determination of iodate in rain water by n.a.a. Iodate is separated by anion exchange. The combination of n.a.a. and solvent extraction is used for the determination of five trace elements (V, Co, Cu, Zn and In) in 10-ml rain water samples. For V, Co and Cu this method is more sensitive and reproducible than instrumental n.a.a. The results of the analysis of eleven sequential 30-ml samples from the beginning of the shower are presented as an illustration of possible applications of the

Development of a low-budget, remote, solar powered, and self-operating rain gauge for spatial rainfall real time data monitoring in pristine and urban areas

Science.gov (United States)

Shafiei Shiva, J.; Chandler, D. G.; Nucera, K. J.; Valinski, N.

2016-12-01

Precipitation is one of the main components of the hydrological cycle and simulations and it is generally stated as an average value for the study area. However, due to high spatial variability of precipitation in some situations, more precise local data is required. In order to acquire the precipitation data, interpolation of neighbor gauged precipitation data is used which is the most affordable technique for a watershed scale study. Moreover, novel spatial rain measurements such as Doppler radars and satellite image processing have been widely used in recent studies. Although, due to impediments in the radar data processing and the effect of the local setting on the accuracy of the interpolated data, the local measurement of the precipitation remains as one of the most reliable approaches in attaining rain data. In this regard, development of a low-budget, remote, solar powered, and self-operating rain gauge for spatial rainfall real time data monitoring for pristine and urban areas has been presented in this research. The proposed rain gauge consists of two main parts: (a) hydraulic instruments and (b) electrical devices. The hydraulic instruments will collect the rain fall and store it in a PVC container which is connected to the high sensitivity pressure transducer systems. These electrical devices will transmit the data via cellphone networks which will be available for further analysis in less than one minute, after processing. The above-mentioned real time rain fall data can be employed in the precipitation measurement and the evaporation estimation. Due to the installed solar panel for battery recharging and designed siphon system for draining cumulative rain, this device is considered as a self-operating rain gauge. At this time, more than ten rain gauges are built and installed in the urban area of Syracuse, NY. Furthermore, these data are also useful for calibration and validation of data obtained by other rain gauging devices and estimation techniques

The Effects of Rain Garden Size on Hydrologic Performance

Science.gov (United States)

Rain gardens are vegetated depressions designed to accept stormwater runoff. Manuals and guidance documents recommend sizing rain garden cells from 3% to 43% of the associated drainage area, based on factors including soil type, slope, amount of impervious cover in the drainage ...

Electron beam treatment technology for exhaust gas for preventing acid rain

International Nuclear Information System (INIS)

Aoki, Shinji

1990-01-01

Recently, accompanying the increase of the use of fossil fuel, the damage due to acid rain such as withering of trees and extinction of fishes and shells has occurred worldwide, and it has become a serious problem. The sulfur oxides and nitrogen oxides contained in exhaust gas are oxidized by the action of sunbeam to become sulfuric acid and nitric acid mists, which fall in the form of rain. Acid rain is closely related to the use of the coal containing high sulfur, and it hinders the use of coal which is rich energy source. In order to simplify the processing system for boiler exhaust gas and to reduce waste water and wastes, Ebara Corp. developed the dry simultaneous desulfurizing and denitrating technology utilizing electron beam in cooperation with Japan Atomic Energy Research Institute. The flow chart of the system applied to the exhaust gas treatment in a coal-fired thermal power station is shown. The mechanism of desulfurization and denitration, and the features of this system are described. The demonstration plant was constructed in a coal-fired thermal power station in Indianapolis, Indiana, USA, and the trial operation was completed in July, 1987. The test results are reported. (K.I.)

Rain-induced subsurface airflow and Lisse effect

Science.gov (United States)

Guo, Haipeng; Jiao, Jiu J.; Weeks, Edwin P.

2008-07-01

Water-level increase after rainfall is usually indicative of rainfall recharge to groundwater. This, however, may not be true if the Lisse effect occurs. This effect represents the water-level increase in a well driven by airflow induced by an advancing wetting front during highly intensive rains. The rainwater, which may behave like a low-permeability lid, seals the ground surface so that the air pressure beneath the wetting front is increased because of air compression due to downward movement of the wetting front. A rapid and substantial rise of the water level in the well screened below water table, which bears no relationship to groundwater recharge, can be induced when various factors such as soil properties and the rain-runoff condition combine favorably. A transient, three-dimensional and variably saturated flow model was employed to study the air and groundwater flows in the soil under rain conditions. The objectives of this paper are two-fold: to evaluate the reliability of the theory of the Lisse effect presented by Weeks to predict its magnitude in modeled situations that mimic the physical complexity of real aquifers, and to conduct parametric studies on the sensitivity of the water-level rise in the well to soil properties and the rain event. The simulation results reveal that the magnitude of the Lisse effect increases with the ponding depth. Soil permeability plays a key role in generating the Lisse effect. The water-level rise in the well is delayed relative to the air-pressure rise in the unsaturated zone when the soil permeability is low, and the maximum water-level rise is less than the maximum air pressure induced by rain infiltration. The simulation also explores the sensitivity of the Lisse effect to the van Genuchten parameters and the water table depth.

Daytime warming has stronger negative effects on soil nematodes than night-time warming

Science.gov (United States)

Yan, Xiumin; Wang, Kehong; Song, Lihong; Wang, Xuefeng; Wu, Donghui

2017-03-01

Warming of the climate system is unequivocal, that is, stronger warming during night-time than during daytime. Here we focus on how soil nematodes respond to the current asymmetric warming. A field infrared heating experiment was performed in the western of the Songnen Plain, Northeast China. Three warming modes, i.e. daytime warming, night-time warming and diurnal warming, were taken to perform the asymmetric warming condition. Our results showed that the daytime and diurnal warming treatment significantly decreased soil nematodes density, and night-time warming treatment marginally affected the density. The response of bacterivorous nematode and fungivorous nematode to experimental warming showed the same trend with the total density. Redundancy analysis revealed an opposite effect of soil moisture and soil temperature, and the most important of soil moisture and temperature in night-time among the measured environment factors, affecting soil nematode community. Our findings suggested that daily minimum temperature and warming induced drying are most important factors affecting soil nematode community under the current global asymmetric warming.

Warm Hydroforming of Lightweight Metal Sheets

International Nuclear Information System (INIS)

Aginagalde, A.; Orus, A.; Esnaola, J. A.; Torca, I.; Galdos, L.; Garcia, C.

2007-01-01

Hydroforming is well known in steel applications for automotive industry, where complicated shapes can be get with high strength to weight ratios. Nevertheless, the poor formability of light alloys at room temperature has limited the application of hydroforming technology for aluminum and magnesium parts. Increasing the temperature of these materials allows substantially greater elongation without fracture. Warm forming strategy is applied in conventional processes, such as rolling and forging, in order to get complex shapes, but still rare in hydroforming technology. This is the technical base of this research project: the development of the hydroforming process at warm working temperatures. The main tasks of the initial phases of the research were the material characterization, and the heated fluid and tooling system design and set up for warm hydroforming of lightweight alloys. Once these goals were accomplished the present paper shows the obtained results. The uniaxial tensile deformation of 5754H111, 6082-T6, 6082-O and AZ31B at the temperature range of 25 deg. C - 250 deg. C is presented as the output of the material characterization task. Both the system features and the results obtained for a bulge test geometry carried out with a warm hydroforming system are also presented. The selected alloys show an improvement in formability at the studied temperature range under both uniaxial and biaxial state of stress

[Relationship between simulated acid rain stress and leaf reflectance].

Science.gov (United States)

Song, Xiao-dong; Jiang, Hong; Yu, Shu-quan; Zhou, Guo-mo; Jiang, Zi-shan

2010-01-01

Acid rain is a worldwide environmental problem. Serious acid rain pollution in subtropical China has constituted a potential threat to the health of the local forest. In the present paper, the changing properties of the chlorophyll concentration and spectral reflectance at the visible wavelengths for the six subtropical broad-leaved tree species leaves under simulated acid rain (SAR) treatment with different pH levels were studied. With the increasing strength of the SAR, the chlorophyll concentrations of the experimental species under pH 2.5 and pH 4.0 treatment were higher than that under pH 5.6; the spectral reflectance at the visible wavelengths for pH 2.5 and pH 4.0 were lower than that for pH 5.6 in general; while there weren't significant differences between pH 2.5 and pH 4.0. After the treatment with different levels of SAR, the differences in spectral reflectance at the visible wavelengths mainly focused around the green peak and red edge on the reflectance curve. The subtropical broad-leaved tree species studied were relatively not sensitive to acid rain stresses; some stronger acid rain may accelerate the growth of the tree species used here to some extent.

Acid rain and its environmental effects: Recent scientific advances

Science.gov (United States)

Burns, Douglas A.; Aherne, Julian; Gay, David A.; Lehmann, Christopher M. B.

2016-12-01

The term 'acid rain' refers to atmospheric deposition of acidic constituents that impact the earth as rain, snow, particulates, gases, and vapor. Acid rain was first recognized by Ducros (1845) and subsequently described by the English chemist Robert Angus Smith (Smith, 1852) whose pioneering studies linked the sources to industrial emissions and included early observations of deleterious environmental effects (Smith, 1872). Smith's work was largely forgotten until the mid-20th century when observations began to link air pollution to the deposition of atmospheric sulfate (SO42-) and other chemical constituents, first near the metal smelter at Sudbury, Ontario, Canada, and later at locations in Europe, North America, and Australia (Gorham, 1961). Our modern understanding of acid rain as an environmental problem caused largely by regional emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) stems from observations in the 1960s and early 1970s in Sweden by Svante Odén (Odén, 1976), and in North America by Gene Likens and colleagues (Likens and Bormann, 1974). These scientists and many who followed showed the link to emissions from coal-fired power plants and other industrial sources, and documented the environmental effects of acid rain such as the acidification of surface waters and toxic effects on vegetation, fish, and other biota.

Monitoring of rain water storage in forests with satellite radar

OpenAIRE

de Jong, JJM; Klaassen, W; Kuiper, PJC

2002-01-01

The sensitivity of radar backscatter to the amount of intercepted rain in temperate deciduous forests is analyzed to determine the feasibility of retrieval of this parameter from satellite radar data. A backscatter model is validated with X-band radar measurements of a single tree exposed to rain. A good agreement between simulation and measurements is observed and this demonstrates the ability of radar to measure the amount of intercepted rain. The backscatter model is next applied to simula...

Damage-controlled logging in managed tropical rain forest in Suriname

OpenAIRE

Hendrison, J.

1990-01-01

Concern about worldwide deforestation and exploitation of the tropical rain forests has led to friction between national governments, wood industries and timber trade on the one hand, and scientists and environmental organizations on the other. One way to safeguard the tropical rain forests is to avoid human interference and to use forests only as nature reserves and as buffer zones of environmental protection. Some vulnerable tropical rain forests and those with unique flora and fau...

Seagrass ecophysiological performance under ocean warming and acidification.

Science.gov (United States)

Repolho, Tiago; Duarte, Bernardo; Dionísio, Gisela; Paula, José Ricardo; Lopes, Ana R; Rosa, Inês C; Grilo, Tiago F; Caçador, Isabel; Calado, Ricardo; Rosa, Rui

2017-02-01

Seagrasses play an essential ecological role within coastal habitats and their worldwide population decline has been linked to different types of anthropogenic forces. We investigated, for the first time, the combined effects of future ocean warming and acidification on fundamental biological processes of Zostera noltii, including shoot density, leaf coloration, photophysiology (electron transport rate, ETR; maximum PSII quantum yield, F v /F m ) and photosynthetic pigments. Shoot density was severely affected under warming conditions, with a concomitant increase in the frequency of brownish colored leaves (seagrass die-off). Warming was responsible for a significant decrease in ETR and F v /F m (particularly under control pH conditions), while promoting the highest ETR variability (among experimental treatments). Warming also elicited a significant increase in pheophytin and carotenoid levels, alongside an increase in carotenoid/chlorophyll ratio and De-Epoxidation State (DES). Acidification significantly affected photosynthetic pigments content (antheraxanthin, β-carotene, violaxanthin and zeaxanthin), with a significant decrease being recorded under the warming scenario. No significant interaction between ocean acidification and warming was observed. Our findings suggest that future ocean warming will be a foremost determinant stressor influencing Z. noltii survival and physiological performance. Additionally, acidification conditions to occur in the future will be unable to counteract deleterious effects posed by ocean warming.

A new method for automated dynamic calibration of tipping-bucket rain gauges

Science.gov (United States)

Humphrey, M.D.; Istok, J.D.; Lee, J.Y.; Hevesi, J.A.; Flint, A.L.

1997-01-01

Existing methods for dynamic calibration of tipping-bucket rain gauges (TBRs) can be time consuming and labor intensive. A new automated dynamic calibration system has been developed to calibrate TBRs with minimal effort. The system consists of a programmable pump, datalogger, digital balance, and computer. Calibration is performed in two steps: 1) pump calibration and 2) rain gauge calibration. Pump calibration ensures precise control of water flow rates delivered to the rain gauge funnel; rain gauge calibration ensures precise conversion of bucket tip times to actual rainfall rates. Calibration of the pump and one rain gauge for 10 selected pump rates typically requires about 8 h. Data files generated during rain gauge calibration are used to compute rainfall intensities and amounts from a record of bucket tip times collected in the field. The system was tested using 5 types of commercial TBRs (15.2-, 20.3-, and 30.5-cm diameters; 0.1-, 0.2-, and 1.0-mm resolutions) and using 14 TBRs of a single type (20.3-cm diameter; 0.1-mm resolution). Ten pump rates ranging from 3 to 154 mL min-1 were used to calibrate the TBRs and represented rainfall rates between 6 and 254 mm h-1 depending on the rain gauge diameter. All pump calibration results were very linear with R2 values greater than 0.99. All rain gauges exhibited large nonlinear underestimation errors (between 5% and 29%) that decreased with increasing rain gauge resolution and increased with increasing rainfall rate, especially for rates greater than 50 mm h-1. Calibration curves of bucket tip time against the reciprocal of the true pump rate for all rain gauges also were linear with R2 values of 0.99. Calibration data for the 14 rain gauges of the same type were very similar, as indicated by slope values that were within 14% of each other and ranged from about 367 to 417 s mm h-1. The developed system can calibrate TBRs efficiently, accurately, and virtually unattended and could be modified for use with other

Assessment of rain water chemistry in the Lucknow metropolitan city

Science.gov (United States)

Sharma, Purnima; Rai, Vibhuti

2018-05-01

Lucknow metropolitan city is one of the most populated cities of India, which have been facing many problems such as chaotic urbanization, overpopulation, water scarcity, waterlogging, etc., among these water scarcity is one of the important problem. Rain water harvesting is a futuristic tool for mitigation of water scarcity problem through conservation and storage of rain water. This rain water can be used for all purposes by human beings, thus it is necessary to check the chemistry of rain water. The rain water samples were collected from the five zones of Lucknow city. For the comparative study, water samples have been collected from two different dates first from first rainfall and second after 3 days of interval in the second rainfall. The heavy metal concentrations were found in both first and second rainfall water samples in all zones of Lucknow city. The concentration of chromium, cadmium and lead were found to be sufficiently high in several samples. These heavy metals show the concentration above the permissible limit as set by WHO, which can cause various adverse health impacts.

Discussions on the Design of the Pool Landscape in the Rain Garden Construction

Science.gov (United States)

Zou, Shuzhen; Zhu, Yirong; Wei, Chaojun; Tao, Biaohong

2018-03-01

With rapid urbanization, the environmental problems are becoming increasingly prominent and diversified ecological landscape designs consequently appear with the rain garden landscape design as a typical. Based on the introduction to rain garden ecological functions and in combination with domestic and international rain garden landscape design cases, this paper discussed the rain garden pool landscape design.

[Characteristics and the impact factors of acid rain in Fuzhou and Xiamen 1992-2012].

Science.gov (United States)

Zheng, Qiu-Ping; Wang, Hong; Chen, Bin-Bin; Sui, Ping; Lin, Wen

2014-10-01

Based on the observed acid rain data, synoptic situations and mass concentrations of atmospheric pollutants data from 1992 to 2012, the temporal variation characteristics and the impact factors of acid rain were analyzed in Fuzhou and Xiamen. The results showed that acid rain and non-acid rain accounted for 38.1% and 61.9% respectively in Fuzhou, 40.6% and 59.4% respectively in Xiamen. The annual average pH was 4.1-5.5 in Fuzhou. Acid rain pollution alleviated after 2007 in Fuzhou, and alleviated after 2006 in Xiamen. Acid rain was more serious in winter and spring than in summer and autumn. Precipitation intensity could affect the acidity of rain. Acid rain was observed more serious in southeast, southwest, west and northwest wind in Fuzhou, and more serious in northeast, southwest, west and northwest wind in Xiamen. Acid rain was most severe under the condition of transformed surface cold high, while most light under the conditions of typhoon (intertropical convergence zone) and outside of typhoon (intertropical convergence zone). There was a negative correlation between the mass concentrations of atmospheric pollutants, such as SO2, NO2, PM10, and the pH of rain in Fuzhou.

Development of a high velocity rain erosion test method

Energy Technology Data Exchange (ETDEWEB)

Chung, Dong Teak; Jin, Doo Han [Korea University of Technology and Education, Cheonan (Korea, Republic of); Kang, Hyung [Agency for Defense Development, Daejeon (Korea, Republic of)

2009-07-01

The nose of a missile, flying through raining region with a supersonic speed, is subjected to the rain erosion because the nose is made of a brittle ceramic material. A simple yet very effective rain erosion test method is developed. The sabot assembly similar to the hypodermic syringe carries specific amount of water is launched by a low pressure air gun. After the stopper stop the sabot assembly by impact, the steel plunger continues moving toward to squeeze the silicon rubber in front. The pressurized silicon rubber then is squeezed through the orifice in front of the sabot at high velocity, thus, accelerates the water droplet to higher velocity. The droplet velocity up to 800m/s is successfully attained using a low pressure air gun. The ceramic specimen assembly is placed in front of the high speed water droplet and the rain erosion damage on the surface of the specimen is observed.

The importance of warm season warming to western U.S. streamflow changes

Science.gov (United States)

Das, T.; Pierce, D.W.; Cayan, D.R.; Vano, J.A.; Lettenmaier, D.P.

2011-01-01

Warm season climate warming will be a key driver of annual streamflow changes in four major river basins of the western U.S., as shown by hydrological model simulations using fixed precipitation and idealized seasonal temperature changes based on climate projections with SRES A2 forcing. Warm season (April-September) warming reduces streamflow throughout the year; streamflow declines both immediately and in the subsequent cool season. Cool season (October-March) warming, by contrast, increases streamflow immediately, partially compensating for streamflow reductions during the subsequent warm season. A uniform warm season warming of 3C drives a wide range of annual flow declines across the basins: 13.3%, 7.2%, 1.8%, and 3.6% in the Colorado, Columbia, Northern and Southern Sierra basins, respectively. The same warming applied during the cool season gives annual declines of only 3.5%, 1.7%, 2.1%, and 3.1%, respectively. Copyright 2011 by the American Geophysical Union.

Low-Latitude Ethane Rain on Titan

Science.gov (United States)

Dalba, Paul A.; Buratti, Bonnie J.; Brown, R. H.; Barnes, J. W.; Baines, K. H.; Sotin, C.; Clark, R. N.; Lawrence, K. J.; Nicholson, P. D.

2012-01-01

Cassini ISS observed multiple widespread changes in surface brightness in Titan's equatorial regions over the past three years. These brightness variations are attributed to rainfall from cloud systems that appear to form seasonally. Determining the composition of this rainfall is an important step in understanding the "methanological" cycle on Titan. I use data from Cassini VIMS to complete a spectroscopic investigation of multiple rain-wetted areas. I compute "before-and-after" spectral ratios of any areas that show either deposition or evaporation of rain. By comparing these spectral ratios to a model of liquid ethane, I find that the rain is most likely composed of liquid ethane. The spectrum of liquid ethane contains multiple absorption features that fall within the 2-micron and 5-micron spectral windows in Titan's atmosphere. I show that these features are visible in the spectra taken of Titan's surface and that they are characteristically different than those in the spectrum of liquid methane. Furthermore, just as ISS saw the surface brightness reverting to its original state after a period of time, I show that VIMS observations of later flybys show the surface composition in different stages of returning to its initial form.

Performance of a rain retrieval algorithm using TRMM data in the Eastern Mediterranean

Directory of Open Access Journals (Sweden)

D. Katsanos

2006-01-01

Full Text Available This study aims to make a regional characterization of the performance of the rain retrieval algorithm BRAIN. This algorithm estimates the rain rate from brightness temperatures measured by the TRMM Microwave Imager (TMI onboard the TRMM satellite. In this stage of the study, a comparison between the rain estimated from Precipitation Radar (PR onboard TRMM (2A25 version 5 and the rain retrieved by the BRAIN algorithm is presented, for about 30 satellite overpasses over the Central and Eastern Mediterranean during the period October 2003–March 2004, in order to assess the behavior of the algorithm in the Eastern Mediterranean region. BRAIN was built and tested using PR rain estimates distributed randomly over the whole TRMM sampling region. Characterization of the differences between PR and BRAIN over a specific region is thus interesting because it might show some local trend for one or the other of the instrument. The checking of BRAIN results against the PR rain-estimate appears to be consistent with former results i.e. a somewhat marked discrepancy for the highest rain rates. This difference arises from a known problem that affect rain retrieval based on passive microwave radiometers measurements, but some of the higher radar rain rates could also be questioned. As an independent test, a good correlation between the rain retrieved by BRAIN and lighting data (obtained by the UK Met. Office long range detection system is also emphasized in the paper.

Little ecological divergence associated with speciation in two African rain forest tree genera

NARCIS (Netherlands)

Couvreur, T.L.P.; Porter-Morgan, H.; Wieringa, J.J.; Chatrou, L.W.

2011-01-01

Background - The tropical rain forests (TRF) of Africa are the second largest block of this biome after the Amazon and exhibit high levels of plant endemism and diversity. Two main hypotheses have been advanced to explain speciation processes that have led to this high level of biodiversity:

Time dependence of the pH of rain

Science.gov (United States)

John A. Kadlecek; Volkar A. Mohnen

1976-01-01

Standard procedures for determining the pH of rain samples usually involve substantial delays from the time of rainfall to the time of analysis. This assumes that no change in pH occurs during the storage period. We have found that this is not always true. We have determined that individual rain water samples possess a time dependent pH which can be correlated with the...

Actual state of plant decline phenomena due to acid rain and others

International Nuclear Information System (INIS)

Yokobori, Makoto

1992-01-01

Recently, Japanese mass communication earnestly reports on the effect that acid rain exerts to natural environment. Also the researches have been carried out on the present state of rainwater acidification, the mechanism of the effect of acid rain to plants, the experiment using artificial acid rain, and the foreign theories on the cause of the decline of forests. But the example of the damage of trees and plants in fields, of which the true cause is understood to be acid rain, is not found. The author has engaged in the research on forest protection for long years, and according to his experience, in the present Japanese research on acid rain, there are a number of important pitfalls. Acid rain theory is only one of many hypotheses. It must be verified by the proper research, and this point is important. Ibaraki Prefectural Forest Experiment station has carried out the consultation on the diagnosis and restoration of tree conditions, and the decline of trees and its cause are reported according to the examples of investigation. In the consultation in the last nine years, the decline of trees caused by acid rain was not confirmed. (K.I.)

Chemical and isotopic methods for characterization of pollutant sources in rain water

International Nuclear Information System (INIS)

Verma, M.P.

1996-01-01

The acid rain formation is related with industrial pollution. An isotopic and chemical study of the spatial and temporary distribution of the acidity in the rain gives information about the acidity source. The predominant species in the acid rain are nitrates and sulfates. For the rain monitoring is required the determination of the anion species such as HCO 3 , Cl, SO 4 , NO 3 and p H. So it was analyzed the cations Na + , K + , Ca 2+ and Mg 2+ to determine the quality analysis. All of them species can be determined with enough accuracy, except HCO 3 by modern equipment such as, liquid chromatograph, atomic absorption, etc. The HCO 3 concentration is determined by traditional methods like acid-base titration. This work presents the fundamental concepts of the titration method for samples with low alkalinity (carbonic species), for rain water. There is presented a general overview over the isotopic methods for the characterization of the origin of pollutant sources in the rain. (Author)

Global warming

International Nuclear Information System (INIS)

Anon.

1992-01-01

Canada's Green Plan strategy for dealing with global warming is being implemented as a multidepartmental partnership involving all Canadians and the international community. Many of the elements of this strategy are built on an existing base of activities predating the Green Plan. Elements of the strategy include programs to limit emissions of greenhouse gases, such as initiatives to encourage more energy-efficient practices and development of alternate fuel sources; studies and policy developments to help Canadians prepare and adapt to climate change; research on the global warming phenomenon; and stimulation of international action on global warming, including obligations arising out of the Framework Convention on Climate Change. All the program elements have been approved, funded, and announced. Major achievements to date are summarized, including improvements in the Energy Efficiency Act, studies on the socioeconomic impacts of global warming, and participation in monitoring networks. Milestones associated with the remaining global warming initiatives are listed

Direct effect of acid rain on leaf chlorophyll content of terrestrial plants in China.

Science.gov (United States)

Du, Enzai; Dong, Dan; Zeng, Xuetong; Sun, Zhengzhong; Jiang, Xiaofei; de Vries, Wim

2017-12-15

Anthropogenic emissions of acid precursors in China have resulted in widespread acid rain since the 1980s. Although efforts have been made to assess the indirect, soil mediated ecological effects of acid rain, a systematic assessment of the direct foliage injury by acid rain across terrestrial plants is lacking. Leaf chlorophyll content is an important indicator of direct foliage damage and strongly related to plant productivity. We synthesized data from published literature on experiments of simulated acid rain, by directly exposing plants to acid solutions with varying pH levels, to assess the direct effect of acid rain on leaf chlorophyll content across 67 terrestrial plants in China. Our results indicate that acid rain substantially reduces leaf chlorophyll content by 6.71% per pH unit across the recorded plant species. The direct reduction of leaf chlorophyll content due to acid rain exposure showed no significant difference across calcicole, ubiquist or calcifuge species, implying that soil acidity preference does not influence the sensitivity to leaf injury by acid rain. On average, the direct effects of acid rain on leaf chlorophyll on trees, shrubs and herbs were comparable. The effects, however varied across functional groups and economic use types. Specifically, leaf chlorophyll content of deciduous species was more sensitive to acid rain in comparison to evergreen species. Moreover, vegetables and fruit trees were more sensitive to acid rain than other economically used plants. Our findings imply a potential production reduction and economic loss due to the direct foliage damage by acid rain. Copyright © 2017 Elsevier B.V. All rights reserved.

Performance of Using Cascade Forward Back Propagation Neural Networks for Estimating Rain Parameters with Rain Drop Size Distribution

Directory of Open Access Journals (Sweden)

Siddi Tengeleng

2014-06-01

Full Text Available The aim of our study is to estimate the parameters M (water content, R (rain rate and Z (radar reflectivity with raindrop size distribution by using the neural network method. Our investigations have been conducted in five African localities: Abidjan (Côte d’Ivoire, Boyele (Congo-Brazzaville, Debuncha (Cameroon, Dakar (Senegal and Niamey (Niger. For the first time, we have predicted the values of the various parameters in each locality after using neural models (LANN which have been developed with locally obtained disdrometer data. We have shown that each LANN can be used under other latitudes to get satisfactory results. Secondly, we have also constructed a model, using as train-data, a combination of data issued from all five localities. With this last model called PANN, we could obtain satisfactory estimates forall localities. Lastly, we have distinguished between stratiform and convective rain while building the neural networks. In fact, using simulation data from stratiform rain situations, we have obtained smaller root mean square errors (RMSE between neural values and disdrometer values than using data issued from convective situations.

Global warming and neurodegenerative disorders: speculations on their linkage.

Science.gov (United States)

Habibi, Laleh; Perry, George; Mahmoudi, Morteza

2014-01-01

Climate change is having considerable impact on biological systems. Eras of ice ages and warming shaped the contemporary earth and origin of creatures including humans. Warming forces stress conditions on cells. Therefore, cells evolved elaborate defense mechanisms, such as creation of heat shock proteins, to combat heat stress. Global warming is becoming a crisis and this process would yield an undefined increasing rate of neurodegenerative disorders in future decades. Since heat stress is known to have a degenerative effects on neurons and, conversely, cold conditions have protective effect on these cells, we hypothesize that persistent heat stress forced by global warming might play a crucial role in increasing neurodegenerative disorders.

Rain pH estimation based on the particulate matter pollutants and wet deposition study.

Science.gov (United States)

Singh, Shweta; Elumalai, Suresh Pandian; Pal, Asim Kumar

2016-09-01

In forecasting of rain pH, the changes caused by particulate matter (PM) are generally neglected. In regions of high PM concentration like Dhanbad, the role of PM in deciding the rain pH becomes important. Present work takes into account theoretical prediction of rain pH by two methods. First method considers only acid causing gases (ACG) like CO2, SO2 and NOx in pH estimation, whereas, second method additionally accounts for effect of PM (ACG-PM). In order to predict the rain pH, site specific deposited dust that represents local PM was studied experimentally for its impact on pH of neutral water. After incorporation of PM correction factor, it was found that, rain pH values estimated were more representative of the observed ones. Fractional bias (FB) for the ACG-PM method reduced to values of the order of 10(-2) from those with order of 10(-1) for the ACG method. The study confirms neutralization of rain acidity by PM. On account of this, rain pH was found in the slightly acidic to near neutral range, despite of the high sulfate flux found in rain water. Although, the safer range of rain pH blurs the severity of acid rain from the picture, yet huge flux of acidic and other ions get transferred to water bodies, soil and ultimately to the ground water system. Simple use of rain pH for rain water quality fails to address the issues of its increased ionic composition due to the interfering pollutants and thus undermines severity of pollutants transferred from air to rain water and then to water bodies and soil. Copyright © 2016 Elsevier B.V. All rights reserved.

Variation of rain intensity and drop size distribution with General Weather Patterns (GWL)

Science.gov (United States)

Ghada, Wael; Buras, Allan; Lüpke, Marvin; Menzel, Annette

2017-04-01

Short-duration rainfall extremes may cause flash floods in certain catchments (e.g. cities or fast responding watersheds) and pose a great risk to affected communities. In order to predict their occurrence under future climate change scenarios, their link to atmospheric circulation patterns needs to be well understood. We used a comprehensive data set of meteorological data (temperature, rain gauge precipitation) and precipitation spectra measured by a disdrometer (OTT PARSIVEL) between October 2008 and June 2010 at Freising, southern Germany. For the 21 months of the study period, we integrated the disdrometer spectra over intervals of 10 minutes to correspond to the temporal resolution of the weather station data and discarded measurements with air temperatures below 0°C. Daily General Weather Patterns ("Großwetterlagen", GWL) were downloaded from the website of the German Meteorological Service. Out of the 29 GWL, 14 were included in the analysis for which we had at least 12 rain events during our study period. For the definition of a rain event, we tested different lengths of minimum inter-event times and chose 30 min as a good compromise between number and length of resulting events; rain events started when more than 0.001 mm/h (sensitivity of the disdrometer) were recorded. The length of the rain events ranged between 10 min and 28 h (median 130 min) with the maximum rain intensity recorded being 134 mm/h on 24-07-2009. Seasonal differences were identified for rain event average intensities and maximum intensities per event. The influence of GWL on rain properties such as rain intensity and drop size distribution per time step and per event was investigated based on the above mentioned rain event definition. Pairwise Wilcoxon-tests revealed that higher rain intensity and larger drops were associated with the GWL "Low over the British Isles" (TB), whereas low rain intensities and less drops per interval were associated with the GWL "High over Central Europe

The Fate of Cool Material in the Hot Corona: Solar Prominences and Coronal Rain

Science.gov (United States)

Liu, Wei; Antolin, Patrick; Sun, Xudong; Vial, Jean-Claude; Berger, Thomas

2017-08-01

As an important chain of the chromosphere-corona mass cycle, some of the million-degree hot coronal mass undergoes a radiative cooling instability and condenses into material at chromospheric or transition-region temperatures in two distinct forms - prominences and coronal rain (some of which eventually falls back to the chromosphere). A quiescent prominence usually consists of numerous long-lasting, filamentary downflow threads, while coronal rain consists of transient mass blobs falling at comparably higher speeds along well-defined paths. It remains puzzling why such material of similar temperatures exhibit contrasting morphologies and behaviors. We report recent SDO/AIA and IRIS observations that suggest different magnetic environments being responsible for such distinctions. Specifically, in a hybrid prominence-coronal rain complex structure, we found that the prominence material is formed and resides near magnetic null points that favor the radiative cooling process and provide possibly a high plasma-beta environment suitable for the existence of meandering prominence threads. As the cool material descends, it turns into coronal rain tied onto low-lying coronal loops in a likely low-beta environment. Such structures resemble to certain extent the so-called coronal spiders or cloud prominences, but the observations reported here provide critical new insights. We will discuss the broad physical implications of these observations for fundamental questions, such as coronal heating and beyond (e.g., in astrophysical and/or laboratory plasma environments).

Sea Ice, Hydrocarbon Extraction, Rain-on-Snow and Tundra Reindeer Nomadism in Arctic Russia

Science.gov (United States)

Forbes, B. C.; Kumpula, T.; Meschtyb, N.; Laptander, R.; Macias-Fauria, M.; Zetterberg, P.; Verdonen, M.

2015-12-01

It is assumed that retreating sea ice in the Eurasian Arctic will accelerate hydrocarbon development and associated tanker traffic along Russia's Northern Sea Route. However, oil and gas extraction along the Kara and Barents Sea coasts will likely keep developing rapidly regardless of whether the Northwest Eurasian climate continues to warm. Less certain are the real and potential linkages to regional biota and social-ecological systems. Reindeer nomadism continues to be a vitally important livelihood for indigenous tundra Nenets and their large herds of semi-domestic reindeer. Warming summer air temperatures over the NW Russian Arctic have been linked to increases in tundra productivity, longer growing seasons, and accelerated growth of tall deciduous shrubs. These temperature increases have, in turn, been linked to more frequent and sustained summer high-pressure systems over West Siberia, but not to sea ice retreat. At the same time, winters have been warming and rain-on-snow (ROS) events have become more frequent and intense, leading to record-breaking winter and spring mortality of reindeer. What is driving this increase in ROS frequency and intensity is not clear. Recent modelling and simulation have found statistically significant near-surface atmospheric warming and precipitation increases during autumn and winter over Arctic coastal lands in proximity to regions of sea-ice loss. During the winter of 2013-14 an extensive and lasting ROS event led to the starvation of 61,000 reindeer out of a population of ca. 300,000 animals on Yamal Peninsula, West Siberia. Historically, this is the region's largest recorded mortality episode. More than a year later, participatory fieldwork with nomadic herders during spring-summer 2015 revealed that the ecological and socio-economic impacts from this extreme event will unfold for years to come. There is an urgent need to understand whether and how ongoing Barents and Kara Sea ice retreat may affect the region's ancient

Nucleation procedures in the restoration of riverine areas of the Mixed Rain Forest, Southern Brazil

Directory of Open Access Journals (Sweden)

Ademir Reis

2009-12-01

Full Text Available Due to its significant importance in the history of the occupation of Southern Brazil, the mixed rain forest, particularly in the Planalto Norte Catarinense, was subjected to intense exploitation as well as the replacement of its original vegetation cover by pasture and agricultural areas. Nowadays, it suffers another great impact which is the homogeneous reforestation with species of Pinus. The present situation is characterized by the need for restoration of the local landscape’s connectivity, which means restoring degraded riverine areas by repairing the connectivity between original fragments and areas to be restored. This study investigated the role of the seed bank and seed rain of preserved adjacent riverine fragments and the efficiency of nucleation procedures in the restoration of degraded riverine areas in Pinus taeda L. producing farms. Samples of the seed bank and seed rain of preserved fragments were collected and techniques of soil transposition and artificial perches were applied in the open degraded areas. The riverine areas demonstrated the potential to initiate the secondary succession process, allowing the formation of initial succession stages. The use of nucleation procedures showed the possibility of accelerating the succession process and indicated the importance of establishing linkage points between open areas and conserved remnants.

URBAN RAIN GAUGE SITING SELECTION BASED ON GIS-MULTICRITERIA ANALYSIS

Directory of Open Access Journals (Sweden)

Y. Fu

2016-06-01

Full Text Available With the increasingly rapid growth of urbanization and climate change, urban rainfall monitoring as well as urban waterlogging has widely been paid attention. In the light of conventional siting selection methods do not take into consideration of geographic surroundings and spatial-temporal scale for the urban rain gauge site selection, this paper primarily aims at finding the appropriate siting selection rules and methods for rain gauge in urban area. Additionally, for optimization gauge location, a spatial decision support system (DSS aided by geographical information system (GIS has been developed. In terms of a series of criteria, the rain gauge optimal site-search problem can be addressed by a multicriteria decision analysis (MCDA. A series of spatial analytical techniques are required for MCDA to identify the prospective sites. With the platform of GIS, using spatial kernel density analysis can reflect the population density; GIS buffer analysis is used to optimize the location with the rain gauge signal transmission character. Experiment results show that the rules and the proposed method are proper for the rain gauge site selection in urban areas, which is significant for the siting selection of urban hydrological facilities and infrastructure, such as water gauge.

Study of 1-min rain rate integration statistic in South Korea

Science.gov (United States)

Shrestha, Sujan; Choi, Dong-You

2017-03-01

The design of millimeter wave communication links and the study of propagation impairments at higher frequencies due to a hydrometeor, particularly rain, require the knowledge of 1-min. rainfall rate data. Signal attenuation in space communication results are due to absorption and scattering of radio wave energy. Radio wave attenuation due to rain depends on the relevance of a 1-min. integration time for the rain rate. However, in practice, securing these data over a wide range of areas is difficult. Long term precipitation data are readily available. However, there is a need for a 1-min. rainfall rate in the rain attenuation prediction models for a better estimation of the attenuation. In this paper, we classify and survey the prominent 1-min. rain rate models. Regression analysis was performed for the study of cumulative rainfall data measured experimentally for a decade in nine different regions in South Korea, with 93 different locations, using the experimental 1-min. rainfall accumulation. To visualize the 1-min. rainfall rate applicable for the whole region for 0.01% of the time, we have considered the variation in the rain rate for 40 stations across South Korea. The Kriging interpolation method was used for spatial interpolation of the rain rate values for 0.01% of the time into a regular grid to obtain a highly consistent and predictable rainfall variation. The rain rate exceeded the 1-min. interval that was measured through the rain gauge compared to the rainfall data estimated using the International Telecommunication Union Radio Communication Sector model (ITU-R P.837-6) along with the empirical methods as Segal, Burgueno et al., Chebil and Rahman, logarithmic, exponential and global coefficients, second and third order polynomial fits, and Model 1 for Icheon regions under the regional and average coefficient set. The ITU-R P. 837-6 exhibits a lower relative error percentage of 3.32% and 12.59% in the 5- and 10-min. to 1-min. conversion, whereas the

Regeneration of monsoon rain forest in northern Australia: the sapling bank

Energy Technology Data Exchange (ETDEWEB)

Russell-Smith, J. [Conservation Commission of the Northern Territory, Palmerston, NT (Australia)

1996-12-01

As part of a wider study examining regeneration pathways in monsoon rain forest vegetation in northern Australia, a one-off, dry season census of saplings was undertaken along transects sampled at each of 33 relatively undisturbed sites broadly representative of the range of regional monsoon rain forest vegetation. Four floristic quadrat groups were derived through TWINSPAN classification. Subsequent analyses involved: (1) comparison of mean dry season stockings of juveniles occurring in different rain forest types, and their structural and environmental correlates; (2) comparison of the contributions of different life forms, and the influence of clonal reproduction in the sapling regeneration banks of different forest types; and (3) exploration of relationships between the distributions of saplings of common tree species with respect to seed bank, floristic, structural, and environmental variables. While data presented here require cautious interpretation given that processes of seedling/sapling recruitment and mortality are highly dynamic, sapling banks were found to be most dense on coarse-textured, moist soils, and least dense on coarse-textured, seasonally dry soils. Canopy cover and fire impact were shown to be highly influential on sapling distribution, especially for saplings of tree species and those growing on seasonally dry sites. Sapling densities were little influenced by proximity to rain forest margins, except for shrubs. The potential for clonal reproduction was significantly greater on dry sites, especially for trees. The majority of saplings sampled were derived from relatively few common, non-clonal, canopy tree species. Sapling distributions of 20 out of 23 common tree species were clumped in the vicinity of conspecific adults; for most species the strength of this relationship was greater than that for any other variable. 55 refs, 1 fig, 6 tabs

The Rain-Powered Cart

Science.gov (United States)

2016-08-05

University of America Press, Washington, DC 20064, USA E-mail: mungan@usna.edu and lipscombe@cua.edu Received 10 May 2016, revised 22 June 2016 Accepted for...renewable energy (Some figures may appear in colour only in the online journal) A familiar problem treats how wet a person walking in rain becomes as they

Urban dew and rain in Paris, France: Occurrence and physico-chemical characteristics

Science.gov (United States)

Beysens, D.; Mongruel, A.; Acker, K.

2017-06-01

This paper summarizes one year (April 2011 to March 2012) measurements on planar condensing surfaces of dew and rain events and related physico-chemical characteristics in the urban environment of Paris (city center). Yearly collected water was 3.48 mm for dew (63 events) and 593 mm for rain (146 events). The latter value compares well with rain data (547 mm and 107 events) collected within 12 km at Paris-Orly airport. An estimation of dew yield based on meteo data gives 2.35 mm and 74 events, to be compared with 17.11 mm and 196 events at Paris-Orly. These differences highlight the large reduction in dew events and dew yields in an urban area as compared to a close rural-like area. This reduction is not due to a sky view reduction but to heat island that increases air temperature and decreases relative humidity. Analysis of dew (34) and rain (77) samples were done concerning pH, electrical conductivity (EC), major anions and cations as well as selected trace metals and other minor ions. Mean pH values are found similar for both, dew (6.5) and rain (6.1), rain being slightly more acidic than dew. The mean dew total ionic content (TIC 1.8 meq/l) and EC value (124 μS/cm) are about four times that of rain (0.45 meq/l; 35 μS/cm), meaning that total dissolved solids in dew is nearly four times that in rain. Sulfate and nitrate are the most acidifying components, calcium the most neutralizing constituent with ratio of mean total acidity/total alkalinity comparable for dew and rain ( 0.9). Sulfate and nitrate have mainly anthropogenic sources, whereas chloride and magnesium are mostly connected with marine air masses. Dew is a considerable factor of wet deposition of pollutants; dew and rain ion concentrations, however, meet the WHO requirements for drinking water.

Characterization of tropical precipitation using drop size distribution and rain rate-radar reflectivity relation

Science.gov (United States)

Das, Saurabh; Maitra, Animesh

2018-04-01

Characterization of precipitation is important for proper interpretation of rain information from remotely sensed data. Rain attenuation and radar reflectivity (Z) depend directly on the drop size distribution (DSD). The relation between radar reflectivity/rain attenuation and rain rate (R) varies widely depending upon the origin, topography, and drop evolution mechanism and needs further understanding of the precipitation characteristics. The present work utilizes 2 years of concurrent measurements of DSD using a ground-based disdrometer at five diverse climatic conditions in Indian subcontinent and explores the possibility of rain classification based on microphysical characteristics of precipitation. It is observed that both gamma and lognormal distributions are performing almost similar for Indian region with a marginally better performance by one model than other depending upon the locations. It has also been found that shape-slope relationship of gamma distribution can be a good indicator of rain type. The Z-R relation, Z = ARb, is found to vary widely for different precipitation systems, with convective rain that has higher values of A than the stratiform rain for two locations, whereas the reverse is observed for the rest of the three locations. Further, the results indicate that the majority of rainfall (>50%) in Indian region is due to the convective rain although the occurrence time of convective rain is low (<10%).

Rain Lõhmus toob mängu kupeldaja / Priit Pullerits

Index Scriptorium Estoniae

Pullerits, Priit, 1965-

2005-01-01

Investeerimispanga Lõhmus, Haavel & Viisemann (LHV) nõukogu esimees on seotud teleäriga ja püüab käivitada uut telekanalit. Vt. samas: Rain Lõhmus vastab küsimustele, mis puudutavad LHVga seotud skandaali mõju panga tegevusele ja käimasolevatele äriasjadele. Lisa: Rain Lõhmus. Vt. samas: Mida Lõhmus teleärist teab?

Global warming and neurodegenerative disorders: speculations on their linkage

Science.gov (United States)

Habibi, Laleh; Perry, George; Mahmoudi, Morteza

2014-01-01

Climate change is having considerable impact on biological systems. Eras of ice ages and warming shaped the contemporary earth and origin of creatures including humans. Warming forces stress conditions on cells. Therefore, cells evolved elaborate defense mechanisms, such as creation of heat shock proteins, to combat heat stress. Global warming is becoming a crisis and this process would yield an undefined increasing rate of neurodegenerative disorders in future decades. Since heat stress is known to have a degenerative effects on neurons and, conversely, cold conditions have protective effect on these cells, we hypothesize that persistent heat stress forced by global warming might play a crucial role in increasing neurodegenerative disorders. PMID:25671171

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

Science.gov (United States)

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 Atmospheric

Unexpected Impacts of Global warming on Extreme Warm Spells

Science.gov (United States)

Sardeshmukh, P. D.; Compo, G. P.; McColl, C.; Penland, C.

2017-12-01

It is generally presumed that the likelihood of extreme warm spells around the globe has increased, and will continue to increase, due to global warming. However, we find that this is generally not true in three very different types of global observational datasets and uncoupled atmospheric model simulations of the 1959 to 2012 period with prescribed observed global SSTs, sea ice, and radiative forcing changes. While extreme warm spells indeed became more common in many regions, in many other regions their likelihood remained almost the same or even decreased from the first half to the second half of this period. Such regions of unexpected changes covered nearly 40 percent of the globe in both winter and summer. The basic reason for this was a decrease of temperature variability in such regions that offset or even negated the effect of the mean temperature shift on extreme warm spell probabilities. The possibility of such an impact on extreme value probabilities was highlighted in a recent paper by Sardeshmukh, Compo, and Penland (Journal of Climate 2015). The consistency of the changes in extreme warm spell probabilities among the different observational datasets and model simulations examined suggests that they are robust regional aspects of global warming associated with atmospheric circulation changes. This highlights the need for climate models to represent not just the mean regional temperature signals but also the changes in subseasonal temperature variability associated with global warming. However, current climate models (both CMIP3 and CMIP5) generally underestimate the magnitude of the changes in the atmospheric circulation and associated temperature variability. A likely major cause of this is their continuing underestimation of the magnitude of the spatial variation of tropical SST trends. By generating an overly spatially bland tropical SST warming in response to changes in radiative forcing, the models spuriously mute tropically

Regional seasonal warming anomalies and land-surface feedbacks

Science.gov (United States)

Coffel, E.; Horton, R. M.

2017-12-01

Significant seasonal variations in warming are projected in some regions, especially central Europe, the southeastern U.S., and central South America. Europe in particular may experience up to 2°C more warming during June, July, and August than in the annual mean, enhancing the risk of extreme summertime heat. Previous research has shown that heat waves in Europe and other regions are tied to seasonal soil moisture variations, and that in general land-surface feedbacks have a strong effect on seasonal temperature anomalies. In this study, we show that the seasonal anomalies in warming are also due in part to land-surface feedbacks. We find that in regions with amplified warming during the hot season, surface soil moisture levels generally decline and Bowen ratios increase as a result of a preferential partitioning of incoming energy into sensible vs. latent. The CMIP5 model suite shows significant variability in the strength of land-atmosphere coupling and in projections of future precipitation and soil moisture. Due to the dependence of seasonal warming on land-surface processes, these inter-model variations influence the projected summertime warming amplification and contribute to the uncertainty in projections of future extreme heat.

Global lake response to the recent warming hiatus

Science.gov (United States)

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.

Radio Frequency Interference: The Study of Rain Effect on Radio Signal Attenuation

International Nuclear Information System (INIS)

Roslan Umar; Roslan Umar; Shahirah Syafa Sulan; Atiq Wahidah Azlan; Zainol Abidin Ibrahim

2015-01-01

The intensity of radio waves received by radio telescopes is always not subject to human control. In the millimetre band, the propagation of the electromagnetic waves is severely affected by rain rate, dust particle size and drop size in the terms of attenuation, noise and depolarization. At the frequency above 10 GHz, the absorption and scattering by rain cause a reduction in the transmitted signal amplitude which will lead to the reducing of the availability, reliability and performance on the communications link. In this study, the rain effect on radio signal has been investigated. Spectrum analyzer and weather stations were used to obtain the RFI level and rain rate data respectively. The radio frequency interference (RFI) pattern due to rain factor was determined. This will benefit radio astronomer in managing sites for radio observation for radio astronomy purposes. (author)

Damage-controlled logging in managed tropical rain forest in Suriname

NARCIS (Netherlands)

Hendrison, J.

1990-01-01

Concern about worldwide deforestation and exploitation of the tropical rain forests has led to friction between national governments, wood industries and timber trade on the one hand, and scientists and environmental organizations on the other. One way to safeguard the tropical rain forests

Acidity and salinity of rain

Energy Technology Data Exchange (ETDEWEB)

Gorham, E

1955-01-01

Analyses of pH, Na, K, Ca, Mg, HCO/sub 3/, Cl, SO/sub 4/, NO/sub 3/, and PO/sub 4/ are recorded for forty-two rain samples collected in the English Lake District between 14 May and 23 October, 1954. NaCl was often an important constituent, and the main source of Na, Mg, and Cl appeared to be sea-spray. SO/sub 4/ was clearly correlated with soot, and free H/sub 2/SO/sub 4/ frequently accounted for an appreciable proportion of total ions. Ca, K, and SO/sub 4/ were correlated to some extent. HCO/sub 3/ was absent from more than half the samples. NO/sub 3/ and PO/sub 4/ were usually low in concentration. Sea-spray influence appeared greatest in autumn, while industrial pollution reached its highest concentration in spring. The ecological significance of the ions in rain is pointed out.

Forecasting The Onset Of The East African Rains

Science.gov (United States)

MacLeod, D.; Palmer, T.

2017-12-01

The timing of the rainy seasons is critical for East Africa, where many livelihoods depend on rain-fed agriculture. The exact onset date of the rains varies from year to year and a delayed start has significant implications for food security. Early warning of anomalous onset can help mitigate risks by informing farmer decisions on crop choice and timing of planting. Onset forecasts may also pre-warn governments and NGOs of upcoming need for financial support and humanitarian intervention. Here we assess the potential to forecast the onset of both the short and long rains over East Africa at subseasonal to seasonal timescales. Based on operational reforecasts from ECMWF, we will demonstrate skilful prediction of onset anomalies. An investigation to determine potential sources of this forecast skill will also be presented. This work has been carried out as part of the project ForPAc: "Towards forecast-based preparedness action".

Redesigning rain gauges network in Johor using geostatistics and simulated annealing

International Nuclear Information System (INIS)

Aziz, Mohd Khairul Bazli Mohd; Yusof, Fadhilah; Daud, Zalina Mohd; Yusop, Zulkifli; Kasno, Mohammad Afif

2015-01-01

Recently, many rainfall network design techniques have been developed, discussed and compared by many researchers. Present day hydrological studies require higher levels of accuracy from collected data. In numerous basins, the rain gauge stations are located without clear scientific understanding. In this study, an attempt is made to redesign rain gauge network for Johor, Malaysia in order to meet the required level of accuracy preset by rainfall data users. The existing network of 84 rain gauges in Johor is optimized and redesigned into a new locations by using rainfall, humidity, solar radiation, temperature and wind speed data collected during the monsoon season (November - February) of 1975 until 2008. This study used the combination of geostatistics method (variance-reduction method) and simulated annealing as the algorithm of optimization during the redesigned proses. The result shows that the new rain gauge location provides minimum value of estimated variance. This shows that the combination of geostatistics method (variance-reduction method) and simulated annealing is successful in the development of the new optimum rain gauge system

Redesigning rain gauges network in Johor using geostatistics and simulated annealing

Science.gov (United States)

Aziz, Mohd Khairul Bazli Mohd; Yusof, Fadhilah; Daud, Zalina Mohd; Yusop, Zulkifli; Kasno, Mohammad Afif

2015-02-01

Recently, many rainfall network design techniques have been developed, discussed and compared by many researchers. Present day hydrological studies require higher levels of accuracy from collected data. In numerous basins, the rain gauge stations are located without clear scientific understanding. In this study, an attempt is made to redesign rain gauge network for Johor, Malaysia in order to meet the required level of accuracy preset by rainfall data users. The existing network of 84 rain gauges in Johor is optimized and redesigned into a new locations by using rainfall, humidity, solar radiation, temperature and wind speed data collected during the monsoon season (November - February) of 1975 until 2008. This study used the combination of geostatistics method (variance-reduction method) and simulated annealing as the algorithm of optimization during the redesigned proses. The result shows that the new rain gauge location provides minimum value of estimated variance. This shows that the combination of geostatistics method (variance-reduction method) and simulated annealing is successful in the development of the new optimum rain gauge system.

Redesigning rain gauges network in Johor using geostatistics and simulated annealing

Energy Technology Data Exchange (ETDEWEB)

Aziz, Mohd Khairul Bazli Mohd, E-mail: mkbazli@yahoo.com [Centre of Preparatory and General Studies, TATI University College, 24000 Kemaman, Terengganu, Malaysia and Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Yusof, Fadhilah, E-mail: fadhilahy@utm.my [Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Daud, Zalina Mohd, E-mail: zalina@ic.utm.my [UTM Razak School of Engineering and Advanced Technology, Universiti Teknologi Malaysia, UTM KL, 54100 Kuala Lumpur (Malaysia); Yusop, Zulkifli, E-mail: zulyusop@utm.my [Institute of Environmental and Water Resource Management (IPASA), Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Kasno, Mohammad Afif, E-mail: mafifkasno@gmail.com [Malaysia - Japan International Institute of Technology (MJIIT), Universiti Teknologi Malaysia, UTM KL, 54100 Kuala Lumpur (Malaysia)

2015-02-03

Recently, many rainfall network design techniques have been developed, discussed and compared by many researchers. Present day hydrological studies require higher levels of accuracy from collected data. In numerous basins, the rain gauge stations are located without clear scientific understanding. In this study, an attempt is made to redesign rain gauge network for Johor, Malaysia in order to meet the required level of accuracy preset by rainfall data users. The existing network of 84 rain gauges in Johor is optimized and redesigned into a new locations by using rainfall, humidity, solar radiation, temperature and wind speed data collected during the monsoon season (November - February) of 1975 until 2008. This study used the combination of geostatistics method (variance-reduction method) and simulated annealing as the algorithm of optimization during the redesigned proses. The result shows that the new rain gauge location provides minimum value of estimated variance. This shows that the combination of geostatistics method (variance-reduction method) and simulated annealing is successful in the development of the new optimum rain gauge system.

Global warming potential of the sulfur-iodine process using life cycle assessment methodology

International Nuclear Information System (INIS)

Lattin, William C.; Utgikar, Vivek P.

2009-01-01

A life cycle assessment (LCA) of one proposed method of hydrogen production - thermochemical water-splitting using the sulfur-iodine cycle couple with a very high-temperature nuclear reactor - is presented in this paper. Thermochemical water-splitting theoretically offers a higher overall efficiency than high-temperature electrolysis of water because heat from the nuclear reactor is provided directly to the hydrogen generation process, instead of using the intermediate step of generating electricity. The primary heat source for the S-I cycle is an advanced nuclear reactor operating at temperatures corresponding to those required by the sulfur-iodine process. This LCA examines the environmental impact of the combined advanced nuclear and hydrogen generation plants and focuses on quantifying the emissions of carbon dioxide per kilogram of hydrogen produced. The results are presented in terms of global warming potential (GWP). The GWP of the system is 2500 g carbon dioxide-equivalent (CO 2 -eq) per kilogram of hydrogen produced. The GWP of this process is approximately one-sixth of that for hydrogen production by steam reforming of natural gas, and is comparable to producing hydrogen from wind- or hydro-electric conventional electrolysis. (author)

A Rain Garden for Our School: Becoming Environmental Stewards

Science.gov (United States)

McFadyen, Joy

2012-01-01

In this article, the author talks about a rain garden project at Hampton Elementary School in Bay City, Michigan. The goal of the project was to slow and filter silt-laden runoff (from parking lots, sidewalks, and playground) on its path to Saginaw Bay in Lake Huron. In addition, doing so, the rain gardens would demonstrate to the township, city,…

Acid rain information book. Second edition

International Nuclear Information System (INIS)

1983-05-01

Potential consequences of widespread acid precipitation are reviewed through an extensive literature search. Major aspects of the acid rain phenomena are discussed, areas of uncertainty identified, and current research summarized

A scattering model for rain depolarization

Science.gov (United States)

Wiley, P. H.; Stutzman, W. L.; Bostian, C. W.

1973-01-01

A method is presented for calculating the amount of depolarization caused by precipitation for a propagation path. In the model the effects of each scatterer and their interactions are accounted for by using a series of simplifying steps. It is necessary only to know the forward scattering properties of a single scatterer. For the case of rain the results of this model for attenuation, differential phase shift, and cross polarization agree very well with the results of the only other model available, that of differential attenuation and differential phase shift. Calculations presented here show that horizontal polarization is more sensitive to depolarization than is vertical polarization for small rain drop canting angle changes. This effect increases with increasing path length.

The Study of Rain Specific Attenuation for the Prediction of Satellite Propagation in Malaysia

Science.gov (United States)

Mandeep, J. S.; Ng, Y. Y.; Abdullah, H.; Abdullah, M.

2010-06-01

Specific attenuation is the fundamental quantity in the calculation of rain attenuation for terrestrial path and slant paths representing as rain attenuation per unit distance (dB/km). Specific attenuation is an important element in developing the predicted rain attenuation model. This paper deals with the empirical determination of the power law coefficients which allow calculating the specific attenuation in dB/km from the knowledge of the rain rate in mm/h. The main purpose of the paper is to obtain the coefficients of k and α of power law relationship between specific attenuation. Three years (from 1st January 2006 until 31st December 2008) rain gauge and beacon data taken from USM, Nibong Tebal have been used to do the empirical procedure analysis of rain specific attenuation. The data presented are semi-empirical in nature. A year-to-year variation of the coefficients has been indicated and the empirical measured data was compared with ITU-R provided regression coefficient. The result indicated that the USM empirical measured data was significantly vary from ITU-R predicted value. Hence, ITU-R recommendation for regression coefficients of rain specific attenuation is not suitable for predicting rain attenuation at Malaysia.

Ülemiste Citysse kasvab innovatsioonikeskus / Rain Laane ; interv. Einar Ellermaa

Index Scriptorium Estoniae

Laane, Rain

2008-01-01

Microsoft Eesti tegevjuht Rain Laane e-riigi arengust ja selle toetamisest riiklikul tasandil, e-riigi innovatsioonikeskuse loomisest, e-riigi lahenduse Brüsselisse müümist takistavatest teguritest. Lisa: Rain Laane teesid loodava innovatsioonikeskuse ülesannetest. Vt. samas: Siim-Valmar Kiisler. Riik peab hakkama e-eksporti toetama!

NESDIS Blended Rain Rate (RR) Products

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The blended Rain Rate (RR) product is derived from multiple sensors/satellites. The blended products were merged from polar-orbiting and geostationary satellite...

Local warming: daily temperature change influences belief in global warming.

Science.gov (United States)

Li, Ye; Johnson, Eric J; Zaval, Lisa

2011-04-01

Although people are quite aware of global warming, their beliefs about it may be malleable; specifically, their beliefs may be constructed in response to questions about global warming. Beliefs may reflect irrelevant but salient information, such as the current day's temperature. This replacement of a more complex, less easily accessed judgment with a simple, more accessible one is known as attribute substitution. In three studies, we asked residents of the United States and Australia to report their opinions about global warming and whether the temperature on the day of the study was warmer or cooler than usual. Respondents who thought that day was warmer than usual believed more in and had greater concern about global warming than did respondents who thought that day was colder than usual. They also donated more money to a global-warming charity if they thought that day seemed warmer than usual. We used instrumental variable regression to rule out some alternative explanations.

Global warming: Economic policy responses

International Nuclear Information System (INIS)

Dornbusch, R.; Poterba, J.M.

1991-01-01

This volume contains the proceedings of a conference that brought together economic experts from Europe, the US, Latin America, and Japan to evaluate key issues in the policy debate in global warming. The following issues are at the center of debates on alternative policies to address global warming: scientific evidence on the magnitude of global warming and the extent to which it is due to human activities; availability of economic tools to control the anthropogenic emissions of greenhouse gases, and how vigorously should they be applied; and political economy considerations which influence the design of an international program for controlling greenhouse gases. Many perspectives are offered on the approaches to remedying environmental problems that are currently being pursued in Europe and the Pacific Rim. Deforestation in the Amazon is discussed, as well as ways to slow it. Public finance assessments are presented of both the domestic and international policy issues raised by plans to levy a tax on the carbon emissions from various fossil fuels. Nine chapters have been processed separately for inclusion in the appropriate data bases

Warm ocean processes and carbon cycling in the Eocene.

Science.gov (United States)

John, Eleanor H; Pearson, Paul N; Coxall, Helen K; Birch, Heather; Wade, Bridget S; Foster, Gavin L

2013-10-28

Sea surface and subsurface temperatures over large parts of the ocean during the Eocene epoch (55.5-33.7 Ma) exceeded modern values by several degrees, which must have affected a number of oceanic processes. Here, we focus on the effect of elevated water column temperatures on the efficiency of the biological pump, particularly in relation to carbon and nutrient cycling. We use stable isotope values from exceptionally well-preserved planktonic foraminiferal calcite from Tanzania and Mexico to reconstruct vertical carbon isotope gradients in the upper water column, exploiting the fact that individual species lived and calcified at different depths. The oxygen isotope ratios of different species' tests are used to estimate the temperature of calcification, which we converted to absolute depths using Eocene temperature profiles generated by general circulation models. This approach, along with potential pitfalls, is illustrated using data from modern core-top assemblages from the same area. Our results indicate that, during the Early and Middle Eocene, carbon isotope gradients were steeper (and larger) through the upper thermocline than in the modern ocean. This is consistent with a shallower average depth of organic matter remineralization and supports previously proposed hypotheses that invoke high metabolic rates in a warm Eocene ocean, leading to more efficient recycling of organic matter and reduced burial rates of organic carbon.

Differential Gene Expression of Longan Under Simulated Acid Rain Stress.

Science.gov (United States)

Zheng, Shan; Pan, Tengfei; Ma, Cuilan; Qiu, Dongliang

2017-05-01

Differential gene expression profile was studied in Dimocarpus longan Lour. in response to treatments of simulated acid rain with pH 2.5, 3.5, and a control (pH 5.6) using differential display reverse transcription polymerase chain reaction (DDRT-PCR). Results showed that mRNA differential display conditions were optimized to find an expressed sequence tag (EST) related with acid rain stress. The potential encoding products had 80% similarity with a transcription initiation factor IIF of Gossypium raimondii and 81% similarity with a protein product of Theobroma cacao. This fragment is the transcription factor activated by second messenger substances in longan leaves after signal perception of acid rain.

Application of Statistical Methods of Rain Rate Estimation to Data From The TRMM Precipitation Radar

Science.gov (United States)

Meneghini, R.; Jones, J. A.; Iguchi, T.; Okamoto, K.; Liao, L.; Busalacchi, Antonio J. (Technical Monitor)

2000-01-01

The TRMM Precipitation Radar is well suited to statistical methods in that the measurements over any given region are sparsely sampled in time. Moreover, the instantaneous rain rate estimates are often of limited accuracy at high rain rates because of attenuation effects and at light rain rates because of receiver sensitivity. For the estimation of the time-averaged rain characteristics over an area both errors are relevant. By enlarging the space-time region over which the data are collected, the sampling error can be reduced. However. the bias and distortion of the estimated rain distribution generally will remain if estimates at the high and low rain rates are not corrected. In this paper we use the TRMM PR data to investigate the behavior of 2 statistical methods the purpose of which is to estimate the rain rate over large space-time domains. Examination of large-scale rain characteristics provides a useful starting point. The high correlation between the mean and standard deviation of rain rate implies that the conditional distribution of this quantity can be approximated by a one-parameter distribution. This property is used to explore the behavior of the area-time-integral (ATI) methods where fractional area above a threshold is related to the mean rain rate. In the usual application of the ATI method a correlation is established between these quantities. However, if a particular form of the rain rate distribution is assumed and if the ratio of the mean to standard deviation is known, then not only the mean but the full distribution can be extracted from a measurement of fractional area above a threshold. The second method is an extension of this idea where the distribution is estimated from data over a range of rain rates chosen in an intermediate range where the effects of attenuation and poor sensitivity can be neglected. The advantage of estimating the distribution itself rather than the mean value is that it yields the fraction of rain contributed by

Raspberry Pi Based Intelligent Wireless Sensor Node for Localized Torrential Rain Monitoring

Directory of Open Access Journals (Sweden)

Zhaozhuo Xu

2016-01-01

Full Text Available Wireless sensor networks are proved to be effective in long-time localized torrential rain monitoring. However, the existing widely used architecture of wireless sensor networks for rain monitoring relies on network transportation and back-end calculation, which causes delay in response to heavy rain in localized areas. Our work improves the architecture by applying logistic regression and support vector machine classification to an intelligent wireless sensor node which is created by Raspberry Pi. The sensor nodes in front-end not only obtain data from sensors, but also can analyze the probabilities of upcoming heavy rain independently and give early warnings to local clients in time. When the sensor nodes send the probability to back-end server, the burdens of network transport are released. We demonstrate by simulation results that our sensor system architecture has potentiality to increase the local response to heavy rain. The monitoring capacity is also raised.

Liquid Film Migration in Warm Formed Aluminum Brazing Sheet

Science.gov (United States)

Benoit, M. J.; Whitney, M. A.; Wells, M. A.; Jin, H.; Winkler, S.

2017-10-01

Warm forming has previously proven to be a promising manufacturing route to improve formability of Al brazing sheets used in automotive heat exchanger production; however, the impact of warm forming on subsequent brazing has not previously been studied. In particular, the interaction between liquid clad and solid core alloys during brazing through the process of liquid film migration (LFM) requires further understanding. Al brazing sheet comprised of an AA3003 core and AA4045 clad alloy, supplied in O and H24 tempers, was stretched between 0 and 12 pct strain, at room temperature and 523K (250 °C), to simulate warm forming. Brazeability was predicted through thermal and microstructure analysis. The rate of solid-liquid interactions was quantified using thermal analysis, while microstructure analysis was used to investigate the opposing processes of LFM and core alloy recrystallization during brazing. In general, liquid clad was consumed relatively rapidly and LFM occurred in forming conditions where the core alloy did not recrystallize during brazing. The results showed that warm forming could potentially impair brazeability of O temper sheet by extending the regime over which LFM occurs during brazing. No change in microstructure or thermal data was found for H24 sheet when the forming temperature was increased, and thus warm forming was not predicted to adversely affect the brazing performance of H24 sheet.

Thyroid storm and warm autoimmune hemolytic anemia.

Science.gov (United States)

Moore, Joseph A; Gliga, Louise; Nagalla, Srikanth

2017-08-01

Graves' disease is often associated with other autoimmune disorders, including rare associations with autoimmune hemolytic anemia (AIHA). We describe a unique presentation of thyroid storm and warm AIHA diagnosed concurrently in a young female with hyperthyroidism. The patient presented with nausea, vomiting, diarrhea and altered mental status. Laboratory studies revealed hemoglobin 3.9g/dL, platelets 171×10 9 L -1 , haptoglobin storm and warm AIHA. She was started on glucocorticoids to treat both warm AIHA and thyroid storm, as well as antithyroid medications, propranolol and folic acid. Due to profound anemia and hemodynamic instability, the patient was transfused two units of uncrossmatched packed red blood cells slowly and tolerated this well. She was discharged on methimazole as well as a prolonged prednisone taper, and achieved complete resolution of the thyrotoxicosis and anemia at one month. Hyperthyroidism can affect all three blood cell lineages of the hematopoietic system. Anemia can be seen in 10-20% of patients with thyrotoxicosis. Several autoimmune processes can lead to anemia in Graves' disease, including pernicious anemia, celiac disease, and warm AIHA. This case illustrates a rarely described presentation of a patient with Graves' disease presenting with concurrent thyroid storm and warm AIHA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relation between tritium concentration and chemical composition in rain at Fukuoka

International Nuclear Information System (INIS)

Hayashi, Y.; Momoshima, N.; Maeda, Y.; Kakiuchi, H.

1999-01-01

Tritium concentrations in rain collected at Fukuoka, Japan from 1982 have been measured. From May 1996 tritium concentrations and chemical species have been analyzed for each rain to examine their relationship. Recent rain was concluded not to be affected by tritium from atmospheric nuclear tests. Tritium concentrations showed a seasonal pattern, high during winter and spring and low during summer and fall and had positive correlations with non-sea-salt SO 4 2- , indicating a long distance of acidic materials as well as tritium from continental China. (author)

Global patterns in lake ecosystem responses to warming based on the temperature dependence of metabolism.

Science.gov (United States)

Kraemer, Benjamin M; Chandra, Sudeep; Dell, Anthony I; Dix, Margaret; Kuusisto, Esko; Livingstone, David M; Schladow, S Geoffrey; Silow, Eugene; Sitoki, Lewis M; Tamatamah, Rashid; McIntyre, Peter B

2017-05-01

Climate warming is expected to have large effects on ecosystems in part due to the temperature dependence of metabolism. The responses of metabolic rates to climate warming may be greatest in the tropics and at low elevations because mean temperatures are warmer there and metabolic rates respond exponentially to temperature (with exponents >1). However, if warming rates are sufficiently fast in higher latitude/elevation lakes, metabolic rate responses to warming may still be greater there even though metabolic rates respond exponentially to temperature. Thus, a wide range of global patterns in the magnitude of metabolic rate responses to warming could emerge depending on global patterns of temperature and warming rates. Here we use the Boltzmann-Arrhenius equation, published estimates of activation energy, and time series of temperature from 271 lakes to estimate long-term (1970-2010) changes in 64 metabolic processes in lakes. The estimated responses of metabolic processes to warming were usually greatest in tropical/low-elevation lakes even though surface temperatures in higher latitude/elevation lakes are warming faster. However, when the thermal sensitivity of a metabolic process is especially weak, higher latitude/elevation lakes had larger responses to warming in parallel with warming rates. Our results show that the sensitivity of a given response to temperature (as described by its activation energy) provides a simple heuristic for predicting whether tropical/low-elevation lakes will have larger or smaller metabolic responses to warming than higher latitude/elevation lakes. Overall, we conclude that the direct metabolic consequences of lake warming are likely to be felt most strongly at low latitudes and low elevations where metabolism-linked ecosystem services may be most affected. © 2016 John Wiley & Sons Ltd.

Analysis of the mixing processes in the subtropical Advancetown Lake, Australia

Science.gov (United States)

Bertone, Edoardo; Stewart, Rodney A.; Zhang, Hong; O'Halloran, Kelvin

2015-03-01

This paper presents an extensive investigation of the mixing processes occurring in the subtropical monomictic Advancetown Lake, which is the main water body supplying the Gold Coast City in Australia. Meteorological, chemical and physical data were collected from weather stations, laboratory analysis of grab samples and an in-situ Vertical Profiling System (VPS), for the period 2008-2012. This comprehensive, high frequency dataset was utilised to develop a one-dimensional model of the vertical transport and mixing processes occurring along the water column. Multivariate analysis revealed that air temperature and rain forecasts enabled a reliable prediction of the strength of the lake stratification. Vertical diffusion is the main process driving vertical mixing, particularly during winter circulation. However, a high reservoir volume and warm winters can limit the degree of winter mixing, causing only partial circulation to occur, as was the case in 2013. This research study provides a comprehensive approach for understanding and predicting mixing processes for similar lakes, whenever high-frequency data are available from VPS or other autonomous water monitoring systems.

Early onset of industrial-era warming across the oceans and continents.

Science.gov (United States)

Abram, Nerilie J; McGregor, Helen V; Tierney, Jessica E; Evans, Michael N; McKay, Nicholas P; Kaufman, Darrell S

2016-08-25

The evolution of industrial-era warming across the continents and oceans provides a context for future climate change and is important for determining climate sensitivity and the processes that control regional warming. Here we use post-ad 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account.

Are climate warming and enhanced atmospheric deposition of sulfur and nitrogen threatening tufa landscapes in Jiuzhaigou National Nature Reserve, Sichuan, China?

Science.gov (United States)

Qiao, Xue; Du, Jie; Lugli, Stefano; Ren, Jinhai; Xiao, Weiyang; Chen, Pan; Tang, Ya

2016-08-15

Massive deposition of calcium carbonate in ambient temperature waters (tufa) can form magnificent tufa landscapes, many of which are designated as protected areas. However, tufa landscapes in many areas are threatened by both local anthropogenic activities and climate change. This study, for the first time, posed the question whether the tufa landscape degradation (characterized by tufa degradation and increased biomass of green algae) in Jiuzhaigou National Nature Reserve of China is partially caused by regional air pollution and climate warming. The results indicate that wet deposition (including rain and snow) polluted by anthropogenic SO2, NOx, and NH3 emissions dissolves exposed tufa and may considerably reduce tufa deposition rate and even cause tufa dissolution within shallow waters. These effects of wet deposition on tufa enhanced as pH of wet deposition decreased from 8.01 to 5.06. Annual Volume Weighted Mean concentration of reactive nitrogen (including NH4(+) and NO3(-)) in wet deposition (26.1μmolL(-1)) was 1.8 times of the corresponding value of runoff (14.8μmolL(-1)) and exceeded China's national standard of total nitrogen in runoff for nature reserves (14.3μmolL(-1)), indicating a direct nitrogen fertilization effect of wet deposition on green algae. As water temperature is the major limiting factor of algal growth in Jiuzhaigou and temperature in the top layer (0-5cm) of runoff (depthclimate warming in this region would favor algal growth. In sum, this study suggests that climate warming and enhanced sulfur and nitrogen deposition have contributed to the current degradation of tufa landscape in Jiuzhaigou, but in order to quantify the contributions, further studies are needed, as many other anthropogenic and natural processes also influence tufa landscape evolution. Copyright © 2016 Elsevier B.V. All rights reserved.

Fungus-Growing Termites Originated in African Rain Forest

DEFF Research Database (Denmark)

Aanen, Duur Kornelis; Eggleton, Paul

2005-01-01

are consumed (cf. [ [1] and [2] ]). Fungus-growing termites are found throughout the Old World tropics, in rain forests and savannas, but are ecologically dominant in savannas [ 3 ]. Here, we reconstruct the ancestral habitat and geographical origin of fungus-growing termites. We used a statistical model...... of habitat switching [ 4 ] repeated over all phylogenetic trees sampled in a Bayesian analysis of molecular data [ 5 ]. Our reconstructions provide strong evidence that termite agriculture originated in African rain forest and that the main radiation leading to the extant genera occurred there. Because...

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

Science.gov (United States)

1998-01-01

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 these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmosphere system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration, (NOAA), has issued an advisory indicating the presence of a strong El Nino condition throughout the winter.For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov

Combined effects of lanthanum (III) chloride and acid rain on photosynthetic parameters in rice.

Science.gov (United States)

Wang, Lihong; Wang, Wen; Zhou, Qing; Huang, Xiaohua

2014-10-01

Rare earth elements (REEs) pollution and acid rain are environmental issues, and their deleterious effects on plants attract worldwide attention. These two issues exist simultaneously in many regions, especially in some rice-growing areas. However, little is known about the combined effects of REEs and acid rain on plants. Here, the combined effects of lanthanum chloride (LaCl3), one type of REE salt, and acid rain on photosynthesis in rice were investigated. We showed that the combined treatment of 81.6 μM LaCl3 and acid rain at pH 4.5 increased net photosynthetic rate (Pn), stomatic conductance (Gs), intercellular CO2 concentration (Ci), Hill reaction activity (HRA), apparent quantum yield (AQY) and carboxylation efficiency (CE) in rice. The combined treatment of 81.6 μM LaCl3 and acid rain at pH 3.5 began to behave toxic effects on photosynthesis (decreasing Pn, Gs, HRA, AQY and CE, and increasing Ci), and the maximally toxic effects were observed in the combined treatment of 2449.0 μM LaCl3 and acid rain at pH 2.5. Moreover, the combined effects of LaCl3 and acid rain on photosynthesis in rice depended on the growth stage of rice, with the maximal effects occurring at the booting stage. Furthermore, the combined treatment of high-concentration LaCl3 and low-pH acid rain had more serious effects on photosynthesis in rice than LaCl3 or acid rain treatment alone. Finally, the combined effect of LaCl3 and acid rain on Pn in rice resulted from the changes in stomatic (Gs, Ci) and non-stomatic (HRA, AQY and CE) factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acid Rain in Niger Delta Region: Implication on Water Resources ...

African Journals Online (AJOL)

This research focused on the effect of acid rain on the water quality of the Niger Delta region of Nigeria. Three hundred water samples were collected: 100 water samples from rain, 100 from open wells and 100 from rivers. The water samples were analysed using the paired t-test and multiple correlation analysis to ascertain ...

Intensified Arctic warming under greenhouse warming by vegetation–atmosphere–sea ice interaction

International Nuclear Information System (INIS)

Jeong, Jee-Hoon; Kug, Jong-Seong; Linderholm, Hans W; Chen, Deliang; Kim, Baek-Min; Jun, Sang-Yoon

2014-01-01

Observations and modeling studies indicate that enhanced vegetation activities over high latitudes under an elevated CO 2 concentration accelerate surface warming by reducing the surface albedo. In this study, we suggest that vegetation-atmosphere-sea ice interactions over high latitudes can induce an additional amplification of Arctic warming. Our hypothesis is tested by a series of coupled vegetation-climate model simulations under 2xCO 2 environments. The increased vegetation activities over high latitudes under a 2xCO 2 condition induce additional surface warming and turbulent heat fluxes to the atmosphere, which are transported to the Arctic through the atmosphere. This causes additional sea-ice melting and upper-ocean warming during the warm season. As a consequence, the Arctic and high-latitude warming is greatly amplified in the following winter and spring, which further promotes vegetation activities the following year. We conclude that the vegetation-atmosphere-sea ice interaction gives rise to additional positive feedback of the Arctic amplification. (letter)

Towards corrosion testing of unglazed solar absorber surfaces in simulated acid rain

International Nuclear Information System (INIS)

Salo, T.; Pehkonen, A.; Konttinen, P.; Lund, P.

2005-01-01

Electrochemical impedance spectroscopy and potentiodynamic polarization tests were utilized for determining corrosion probabilities of unglazed C/Al 2 O 3 /Al solar absorber surfaces in simulated acid rain. Previously, the main degradation mechanism found was exponentially temperature-related hydration of aluminium oxide. In acid rain tests the main corrosion determinant was the pH value of the rain. Results indicate that these methods measure corrosion characteristics of Al substrate instead of the C/Al 2 O 3 /Al surface, probably mainly due to the rough and non-uniform microstructure of the latter. Further analyses of the test methods are required in order to estimate their applicability on Al-based uniform sputtered absorber surfaces. (author) (C/Al 2 O 3 /Al solar absorber; Acid rain; Corrosion; Electrochemical tests)

Erosion by rain in the western Congo

International Nuclear Information System (INIS)

Ploey, J. de

1967-01-01

Vast expanses of the western part of central and southern Africa are covered with uniform, sandy formations of the Kalahari type. The topography of these areas and their present morphological characteristics are mainly the result of erosion by rain. Information on the hydrology of the surface waters in these areas is fairly limited and is insufficient to permit any conclusions regarding the way in which erosion by rain takes place. To obtain a better understanding of these phenomena, the author devised a series of experiments based on the use of 46 Sc-labelled radioactive sand. These experiments began at the beginning of the 1964/65 rainy season and are continuing. The experimental plot corresponds to convex and rectilinear portions of a hillside with a slope varying between 0 and 12 degrees. The vegetation consists of grassy savannah of substeppe appearance and secondary forests. Series of labelled samples were placed successively on the surface of the experimental plot and the erosive effect of rain was determined by measuring the residual concentrations after rainfall. Some samples were placed below a shield so as to eliminate the effects of splash and reveal the part played by runoff. Radiographic films were used to study the dispersion of labelled particles in the surrounding area. This radiographic method made it possible to determine the scale of erosion by splash for different rainfall conditions. The erosion diagrams obtained from these experiments show the correlations that exist between the intensity and duration of the rainfall and the erosion of the soil. Examination of the erosion diagrams and the shielded samples and analysis of the radiographs showed that erosion by rain on Kalahari ground covered with substeppe savannah is caused mainly by splash erosion and by dispersed, intermittent runoff. Sheet wash plays no part if the slope is less than 12 degrees. (author) [fr

Global warming-setting the stages

International Nuclear Information System (INIS)

1994-01-01

Most of us have heard or read about global warming. However, the messages we receive are often in conflict, raising more questions than answer. Is global warming a good or a bad thing? has it already started or is it part of our future? Are we, or are we not doing anything about it? Should we be concerned? This primer on Global Warming is designed to clear up some of this confusion by providing basic scientific information on global warming issue. It is clear that there is still much to learn about global warming. However, it is also clear that there is a lot that we already know - and that dose provide cause for concern. We must understand the global warming issue if we are to make wise decisions and take responsible actions in response to the challenges and opportunities posed by global warming. Chapter 1 of 'the primer on global Warming' set the stage with a brief overview of science of global warming within the context of climate change. In addition, it introduces the specific issues that surround the global warming problem. As far as the science of global warming is concerned the following questions are discussed. What is global climate? Is climate change natural? What causes climate to vary on a global scale? How does the composition of the atmosphere relate to climate change. but there are also certain issues discussed here which surround the global warming such as: If climate varies naturally, why is there a concern about 'global warming'? What are the potential consequences of 'global warning'. What human activities contribute to 'global warming'. (Author)

Delineation of Rain Areas with TRMM Microwave Observations Based on PNN

Directory of Open Access Journals (Sweden)

Shiguang Xu

2014-12-01

Full Text Available False alarm and misdetected precipitation are prominent drawbacks of high-resolution satellite precipitation datasets, and they usually lead to serious uncertainty in hydrological and meteorological applications. In order to provide accurate rain area delineation for retrieving high-resolution precipitation datasets using satellite microwave observations, a probabilistic neural network (PNN-based rain area delineation method was developed with rain gauge observations over the Yangtze River Basin and three parameters, including polarization corrected temperature at 85 GHz, difference of brightness temperature at vertically polarized 37 and 19 GHz channels (termed as TB37V and TB19V, respectively and the sum of TB37V and TB19V derived from the observations of the Tropical Rainfall Measuring Mission (TRMM Microwave Imager (TMI. The PNN method was validated with independent samples, and the performance of this method was compared with dynamic cluster K-means method, TRMM Microwave Imager (TMI Level 2 Hydrometeor Profile Product and the threshold method used in the Scatter Index (SI, a widely used microwave-based precipitation retrieval algorithm. Independent validation indicated that the PNN method can provide more reasonable rain areas than the other three methods. Furthermore, the precipitation volumes estimated by the SI algorithm were significantly improved by substituting the PNN method for the threshold method in the traditional SI algorithm. This study suggests that PNN is a promising way to obtain reasonable rain areas with satellite observations, and the development of an accurate rain area delineation method deserves more attention for improving the accuracy of satellite precipitation datasets.

Assessing forest vulnerability to climate warming using a process-based model of tree growth: bad prospects for rear-edges.

Science.gov (United States)

Sánchez-Salguero, Raúl; Camarero, Jesus Julio; Gutiérrez, Emilia; González Rouco, Fidel; Gazol, Antonio; Sangüesa-Barreda, Gabriel; Andreu-Hayles, Laia; Linares, Juan Carlos; Seftigen, Kristina

2017-07-01

Growth models can be used to assess forest vulnerability to climate warming. If global warming amplifies water deficit in drought-prone areas, tree populations located at the driest and southernmost distribution limits (rear-edges) should be particularly threatened. Here, we address these statements by analyzing and projecting growth responses to climate of three major tree species (silver fir, Abies alba; Scots pine, Pinus sylvestris; and mountain pine, Pinus uncinata) in mountainous areas of NE Spain. This region is subjected to Mediterranean continental conditions, it encompasses wide climatic, topographic and environmental gradients, and, more importantly, it includes rear-edges of the continuous distributions of these tree species. We used tree-ring width data from a network of 110 forests in combination with the process-based Vaganov-Shashkin-Lite growth model and climate-growth analyses to forecast changes in tree growth during the 21st century. Climatic projections were based on four ensembles CO 2 emission scenarios. Warm and dry conditions during the growing season constrain silver fir and Scots pine growth, particularly at the species rear-edge. By contrast, growth of high-elevation mountain pine forests is enhanced by climate warming. The emission scenario (RCP 8.5) corresponding to the most pronounced warming (+1.4 to 4.8 °C) forecasted mean growth reductions of -10.7% and -16.4% in silver fir and Scots pine, respectively, after 2050. This indicates that rising temperatures could amplify drought stress and thus constrain the growth of silver fir and Scots pine rear-edge populations growing at xeric sites. Contrastingly, mountain pine growth is expected to increase by +12.5% due to a longer and warmer growing season. The projections of growth reduction in silver fir and Scots pine portend dieback and a contraction of their species distribution areas through potential local extinctions of the most vulnerable driest rear-edge stands. Our modeling

Rain drop size densities over land and over sea

Science.gov (United States)

Bumke, Karl

2010-05-01

A detailed knowledge of rain drop size densities is an essential presumption with respect to remote sensing of precipitation. Since maritime and continental aerosol is significantly different yielding to differences in cloud drop size densities, maritime and continental rain drop size densities may be different, too. In fact only a little is known about differences in rain drop size densities between land and sea due to a lack of suitable data over the sea. To fill in this gap measurements were performed during the recent 10 years at different locations in Germany and on board of research vessels over the Baltic Sea, the North Sea, Atlantic, Indian, and Pacific Ocean. Measurements were done by using an optical disdrometer (ODM 470, Großklaus et al., 1998), which is designed especially to perform precipitation measurements on moving ships and under high wind speeds. Temporal resolution of measurements is generally 1 minute, total number of time series is about 220000. To investigate differences in drop size densities over land and over sea measurements have been divided into four classes on the basis of prevailing continental or maritime influence: land measurements, coastal measurements, measurements in areas of semi-enclosed seas, and open sea measurements. In general differences in drop size densities are small between different areas. A Kolmogoroff Smirnoff test does not give any significant difference between drop size densities over land, coastal areas, semi-enclosed, and open seas at an error rate of 5%. Thus, it can be concluded that there are no systematic differences between maritime and continental drop size densities. The best fit of drop size densities is an exponential decay curve, N(D ) = 6510m -3mm -1mm0.14h- 0.14×R-0.14×exp(- 4.4mm0.25h-0.25×R- 0.25×D mm -1), it is estimated by using the method of least squares. N(D) is the drop size density normalized by the resolution of the optical disdrometer, D the diameter of rain drops in mm, and R the

Detecting Climate Signals in Precipitation Extremes from TRMM (1998-2013) - Increasing Contrast Between Wet and Dry Extremes During the "Global Warming Hiatus"

Science.gov (United States)

Wu, Huey-Tzu Jenny; Lau, William K.-M.

2016-01-01

We investigate changes in daily precipitation extremes using Tropical Rainfall Measuring Mission (TRMM) data (1998-2013), which coincides with the "global warming hiatus." Results show a change in probability distribution functions of local precipitation events (LPEs) during this period consistent with previous global warming studies, indicating increasing contrast between wet and dry extremes, with more intense LPE, less moderate LPE, and more dry (no rain) days globally. Analyses for land and ocean separately reveal more complex and nuanced changes over land, characterized by a strong positive trend (+12.0% per decade, 99% confidence level (c.l.)) in frequency of extreme LPEs over the Northern Hemisphere extratropics during the wet season but a negative global trend (-6.6% per decade, 95% c.l.) during the dry season. A significant global drying trend (3.2% per decade, 99% c.l.) over land is also found during the dry season. Regions of pronounced increased dry events include western and central U.S., northeastern Asia, and Southern Europe/Mediterranean.

A simple model for the estimation of rain-induced attenuation along earth-space paths at millimeter wavelengths

Science.gov (United States)

Stutzman, W. L.; Dishman, W. K.

1982-01-01

A simple attenuation model (SAM) is presented for estimating rain-induced attenuation along an earth-space path. The rain model uses an effective spatial rain distribution which is uniform for low rain rates and which has an exponentially shaped horizontal rain profile for high rain rates. When compared to other models, the SAM performed well in the important region of low percentages of time, and had the lowest percent standard deviation of all percent time values tested.

Direct effect of acid rain on leaf chlorophyll content of terrestrial plants in China

NARCIS (Netherlands)

Du, Enzai; Dong, Dan; Zeng, Xuetong; Sun, Zhengzhong; Jiang, Xiaofei; Vries, de Wim

2017-01-01

Anthropogenic emissions of acid precursors in China have resulted in widespread acid rain since the 1980s. Although efforts have been made to assess the indirect, soil mediated ecological effects of acid rain, a systematic assessment of the direct foliage injury by acid rain across terrestrial

Comparison of Instantaneous Frequency Scaling from Rain Attenuation and Optical Disdrometer Measurements at K/Q bands

Science.gov (United States)

Nessel, James; Zemba, Michael; Luini, Lorenzo; Riva, Carlo

2015-01-01

Rain attenuation is strongly dependent on the rain rate, but also on the rain drop size distribution (DSD). Typically, models utilize an average drop size distribution, such as those developed by Laws and Parsons, or Marshall and Palmer. However, individual rain events may possess drop size distributions which could be significantly different from the average and will impact, for example, fade mitigation techniques which utilize channel performance estimates from a signal at a different frequency. Therefore, a good understanding of the characteristics and variability of the raindrop size distribution is extremely important in predicting rain attenuation and instantaneous frequency scaling parameters on an event-toevent basis. Since June 2014, NASA Glenn Research Center (GRC) and the Politecnico di Milano (POLIMI) have measured the attenuation due to rain in Milan, Italy, on the 20/40 GHz beacon signal broadcast from the Alphasat TDP#5 Aldo Paraboni Q/V-band Payload. Concomitant with these measurements are the measurements of drop size distribution and rain rate utilizing a Thies Clima laser precipitation monitor (disdrometer). In this paper, we discuss the comparison of the predicted rain attenuation at 20 and 40 GHz derived from the drop size distribution data with the measured rain attenuation. The results are compared on statistical and real-time bases. We will investigate the performance of the rain attenuation model, instantaneous frequency scaling, and the distribution of the scaling factor. Further, seasonal rain characteristics will be analysed.

Phenomena associated with rain deposition of radon daughters

Energy Technology Data Exchange (ETDEWEB)

Fujitaka, Kazunobu [National Inst. of Radiological Sciences, Chiba (Japan)

1997-02-01

Since Rn daughter nuclides generated from Rn gas in the air are generally absorbed on aerosol, its radioactivities are apt to deposit onto the ground with raindrop. Here, the effects of raining on the radiation level were investigated. The amount of precipitation was determined using a highly sensitive rain gauge (the nominal sensitivity of 0.0043 mm) and air radioactive level was measured using a scintillation monitor of 2``{phi}x2``NaI(Tl) which was set at 1.5 m height above the ground. The rising of {gamma}-radiation level associated with rainfall was expressed as percentage of the base line activity. The radiation level increased depending on the intervals between the successive rainfalls and the increase of radioactivity from base line was greater when the rainfall interval was less than 12 hours. Therefore, the amount of radiation deposit was suggested to be small when the rainfall interval is short. Ordinarily, the increase of air radiation level caused by rain deposition was thought to be within a range of 20-50%. (M.N.)

Acid-rain induced changes in streamwater quality during storms on Catoctin Mountain, Maryland

Science.gov (United States)

Rice, Karen C.; Bricker, O.P.

1992-01-01

Catoctin Mountain receives some of the most acidic (lowest pH) rain in the United States. In 1990, the U.S. Geological Survey (USGS), in cooperation with the Maryland Department of the Environment (MDE) and the Maryland Department of Natural Resources (DNR), began a study of the effects of acid rain on the quality of streamwater on the part of Catoctin Mountain within Cunningham Falls State Park, Maryland (fig. 1). Samples of precipitation collected on the mountain by the USGS since 1982 have been analyzed for acidity and concentration of chemical constituents. During 1982-91, the volume-weighted average pH of precipitation was 4.2. (Volume weighting corrects for the effect of acids being washed out of the atmosphere at the beginning of rainfall). The pH value is measured on a logarithmic scale, which means that for each whole number change, the acidity changes by a factor of 10. Thus rain with a pH of 4.2 is more than 10 times as acidic as uncontaminated rain, which has a pH of about 5.6. The acidity of rain during several rainstorms on Catoctin Mountain was more than 100 times more acidic than uncontaminated rain.

Visualization of soil-moisture change in response to precipitation within two rain gardens in Ohio

Science.gov (United States)

Dumouchelle, Denise H.; Darner, Robert A.

2014-01-01

Stormwater runoff in urban areas is increasingly being managed by means of a variety of treaments that reduce or delay runoff and promote more natural infiltration. One such treatment is a rain garden, which is built to detain runoff and allow for water infiltration and uptake by plants.Water flow into or out of a rain garden can be readily monitored with a variety of tools; however, observing the movement of water within the rain garden is less straightforward. Soil-moisture probes in combination with an automated interpolation procedure were used to document the infiltration of water into two rain gardens in Ohio. Animations show changes in soil moisture in the rain gardens during two precipitation events. At both sites, the animations demonstrate underutilization of the rain gardens.

Three-moment representation of rain in a cloud microphysics model

Science.gov (United States)

Paukert, M.; Fan, J.; Rasch, P. J.; Morrison, H.; Milbrandt, J.; Khain, A.; Shpund, J.

2017-12-01

Two-moment microphysics schemes have been commonly used for cloud simulation in models across different scales - from large-eddy simulations to global climate models. These schemes have yielded valuable insights into cloud and precipitation processes, however the size distributions are limited to two degrees of freedom, and thus the shape parameter is typically fixed or diagnosed. We have developed a three-moment approach for the rain category in order to provide an additional degree of freedom to the size distribution and thereby improve the cloud microphysics representations for more accurate weather and climate simulations. The approach is applied to the Predicted Particle Properties (P3) scheme. In addition to the rain number and mass mixing ratios predicted in the two-moment P3, we now include prognostic equations for the sixth moment of the size distribution (radar reflectivity), thus allowing the shape parameter to evolve freely. We employ the spectral bin microphysics (SBM) model to formulate the three-moment process rates in P3 for drop collisions and breakup. We first test the three-moment scheme with a maritime stratocumulus case from the VOCALS field campaign, and compare the model results with respect to cloud and precipitation properties from the new P3 scheme, original two-moment P3 scheme, SBM, and in-situ aircraft measurements. The improved simulation results by the new P3 scheme will be discussed and physically explained.

Activity of earthworm in Latosol under simulated acid rain stress

Science.gov (United States)

Jia-En Zhang; Jiayu Yu; Ying Ouyang

2015-01-01

Acid rain is still an issue of environmental concerns. This study investigated the impacts of simulated acid rain (SAR) upon earthworm activity from the Latosol (acidic red soil). Laboratory experiment was performed by leaching the soil columns grown with earthworms (Eisenia fetida) at the SAR pH levels ranged from 2.0 to 6.5 over a 34-day period....

Simulated acid rain effects on soil chemistry and microbiology

International Nuclear Information System (INIS)

Gigliotti, C.; Falappi, D.; Farini, A.; Sorlini, C.; Milan Univ.; Molise Univ.

1992-01-01

A research study was carried out regarding the effects of artificial rains at different pH's (3.1, 4.0, 5.6) on soil samples from Appiano Gentile pinewood. Chemical parameters, biological activities and microbiological groups, particularly sensitive to possible variations in the presence of pH changes, were monitored after 2, 4 and 6 months of treatment of the soil on eluate obtained from treatment with artificial acid rains. The paper reports the results research

Quantifying Regional Vegetation Changes in China During Three Contrasting Warming Intervals since the Last Glacial Maximum

Science.gov (United States)

Li, Q.; Wu, H.; Yu, Y.; Sun, A.; Luo, Y.

2017-12-01

Reconstructing patterns of past vegetation change on a large-scale facilitates a better understanding of the interactions and feedbacks between climate change and the terrestrial biosphere. In addition, reducing the uncertainty in predictions of vegetation change under global warming highlights the importance of reconstructing vegetation patterns during past warming intervals. Here, we present a quantitative regional vegetation reconstruction for China during three intervals: Last Glacial Maximum (LGM, 18±2 14C kyr B.P.), early Holocene (8.5±0.5 14C kyr B.P.), and mid-Holocene (6±0.5 14C kyr B.P.). The biomization method, based on 249 pollen records, was used for the reconstructions. The results demonstrate that during the LGM, steppe and desert expanded eastwards and southwards, reaching the present-day temperate deciduous forest (TEDE) zone, and dominated northern China. In contrast, the forest in Eastern China underwent a substantial southwards retreat and the percentage of forest-type sites was at a minimum. In addition, the warm mixed forest (WAMF) and TEDE shifted southwards of 10° N relative to the present-day, and tropical seasonal rain forest (TSFO) was almost absent. At the same time, the forest-steppe boundary shifted southwards to near the middle and lower reaches of Yangtze River. For the early Holocene and mid-Holocene, the TSFO, WAMF, and TEDE shifted northwards by 2-5° relative to today, and the percentage of forest sites increased and reached a maximum in the mid-Holocene. The slight expansion of forest from the early Holocene to the mid-Holocene caused the forest-steppe boundary to shift northwestwards to near the present-day 300 mm isohyet by the mid-Holocene. Our results also indicate that climatic warming since the LGM, which strengthened the East Asian summer monsoon, favored the development of forest in China. This is potentially an important finding for evaluating the possible response of forest in China to future global warming.

Efficient inhibition of heavy metal release from mine tailings against acid rain exposure by triethylenetetramine intercalated montmorillonite (TETA-Mt).

Science.gov (United States)

Gong, Beini; Wu, Pingxiao; Huang, Zhujian; Li, Yuanyuan; Yang, Shanshan; Dang, Zhi; Ruan, Bo; Kang, Chunxi

2016-11-15

The potential application of triethylenetetramine intercalated montmorillonite (TETA-Mt) in mine tailings treatment and AMD (acid mine drainage) remediation was investigated with batch experiments. The structural and morphological characteristics of TETA-Mt were analyzed with XRD, FTIR, DTG-TG and SEM. The inhibition efficiencies of TETA-Mt against heavy metal release from mine tailings when exposed to acid rain leaching was examined and compared with that of triethylenetetramine (TETA) and Mt. Results showed that the overall inhibition by TETA-Mt surpassed that by TETA or Mt for various heavy metal ions over an acid rain pH range of 3-5.6 and a temperature range of 25-40°C. When mine tailings were exposed to acid rain of pH 4.8 (the average rain pH of the mining site where the mine tailings were from), TETA-Mt achieved an inhibition efficiency of over 90% for Cu(2+), Zn(2+), Cd(2+) and Mn(2+) release, and 70% for Pb(2+) at 25°C. It was shown that TETA-Mt has a strong buffering capacity. Moreover, TETA-Mt was able to adsorb heavy metal ions and the adsorption process was fast, suggesting that coordination was mainly responsible. These results showed the potential of TETA-Mt in AMD mitigation, especially in acid rain affected mining area. Copyright © 2016 Elsevier B.V. All rights reserved.

Leaching Characteristics of Calcium and Strontium from Phosphogypsum Under Acid Rain.

Science.gov (United States)

Wang, Mei; Luo, Houqiao; Chen, Yong; Yang, Jinyan

2018-02-01

Phosphogypsum (PG) stored close to phosphorus chemical plants has caused worldwide environmental problems. Column leaching experiments were conducted to evaluate Ca and Sr leaching from PG under simulated acid rain at pH levels typical for rain in the study region (Shifang, China). High concentrations of Ca and Sr in leachates in the first five leaching events could pollute the soil and groundwater around the PG. Leachates pH was lower than and had no correlation with simulated rain pH. No correlations between simulated rain pH and cumulative Ca and Sr content in leachates were noted. Around 2.0%-2.2% of Ca and 0.5%-0.6% of Sr were leached out from PG by the simulated summer rainfall in Shifang. Electrical conductivity values, Ca and Sr concentrations at bottom sections of PG columns were higher than those of top sections, while pH values showed a reverse trend. More precautions should be taken to protect the environment around PG stacks.

Integrated gasification combined cycle for acid rain control

Energy Technology Data Exchange (ETDEWEB)

Simbeck, D.R.; Dickenson, R.L.

1986-10-01

The role of integrated coal gasification combined-cycle power plants in the abatement of emission of SO/sub 2/ and NO/sub 2/ which lead to acid rain is discussed. The economics of this IGCC approach are assessed for a nominal 500 MW plant size. Phased construction of IGCC plants is recommended as a means of reducing SO/sub 2/ and NO/sub x/ emissions noting that high-sulfur coals could continue to be used. It is also noted that phased construction IGCC is the only acid rain control technology that greatly reduces NO/sub x/. 17 references.

Acid rain and its environmental effects: Recent scientific advances

Science.gov (United States)

Burns, Douglas A.; Aherne, Julian; Gay, David A.; Lehmann, Christopher M.B.

2016-01-01

The term ‘acid rain’ refers to atmospheric deposition of acidic constituents that impact the earth as rain, snow, particulates, gases, and vapor. Acid rain was first recognized by Ducros (1845) and subsequently described by the English chemist Robert Angus Smith (Smith, 1852) whose pioneering studies linked the sources to industrial emissions and included early observations of deleterious environmental effects (Smith, 1872). Smith's work was largely forgotten until the mid-20th century when observations began to link air pollution to the deposition of atmospheric sulfate (SO42−) and other chemical constituents, first near the metal smelter at Sudbury, Ontario, Canada, and later at locations in Europe, North America, and Australia (Gorham, 1961). Our modern understanding of acid rain as an environmental problem caused largely by regional emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) stems from observations in the 1960s and early 1970s in Sweden by Svante Odén (Odén, 1976), and in North America by Gene Likens and colleagues (Likens and Bormann, 1974). These scientists and many who followed showed the link to emissions from coal-fired power plants and other industrial sources, and documented the environmental effects of acid rain such as the acidification of surface waters and toxic effects on vegetation, fish, and other biota.

Circumpolar dynamics of a marine top-predator track ocean warming rates.

Science.gov (United States)

Descamps, Sébastien; Anker-Nilssen, Tycho; Barrett, Robert T; Irons, David B; Merkel, Flemming; Robertson, Gregory J; Yoccoz, Nigel G; Mallory, Mark L; Montevecchi, William A; Boertmann, David; Artukhin, Yuri; Christensen-Dalsgaard, Signe; Erikstad, Kjell-Einar; Gilchrist, H Grant; Labansen, Aili L; Lorentsen, Svein-Håkon; Mosbech, Anders; Olsen, Bergur; Petersen, Aevar; Rail, Jean-Francois; Renner, Heather M; Strøm, Hallvard; Systad, Geir H; Wilhelm, Sabina I; Zelenskaya, Larisa

2017-09-01

Global warming is a nonlinear process, and temperature may increase in a stepwise manner. Periods of abrupt warming can trigger persistent changes in the state of ecosystems, also called regime shifts. The responses of organisms to abrupt warming and associated regime shifts can be unlike responses to periods of slow or moderate change. Understanding of nonlinearity in the biological responses to climate warming is needed to assess the consequences of ongoing climate change. Here, we demonstrate that the population dynamics of a long-lived, wide-ranging marine predator are associated with changes in the rate of ocean warming. Data from 556 colonies of black-legged kittiwakes Rissa tridactyla distributed throughout its breeding range revealed that an abrupt warming of sea-surface temperature in the 1990s coincided with steep kittiwake population decline. Periods of moderate warming in sea temperatures did not seem to affect kittiwake dynamics. The rapid warming observed in the 1990s may have driven large-scale, circumpolar marine ecosystem shifts that strongly affected kittiwakes through bottom-up effects. Our study sheds light on the nonlinear response of a circumpolar seabird to large-scale changes in oceanographic conditions and indicates that marine top predators may be more sensitive to the rate of ocean warming rather than to warming itself. © 2017 John Wiley & Sons Ltd.

Global Warming: A Reduced Threat?.

Science.gov (United States)

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.

Promoting nitrate removal in rain gardens

Science.gov (United States)

Rain gardens are vegetated surface depressions, often located at low points in landscapes, designed to receive stormwater runoff from roads, roofs, and parking lots. The gardens’ sandy soils allow stormwater to drain quickly to the native soils below and eventually to groundwate...

Distribution of rain height over subtropical region: Durban, South Africa for satellite communication systems

Science.gov (United States)

Olurotimi, E. O.; Sokoya, O.; Ojo, J. S.; Owolawi, P. A.

2018-03-01

Rain height is one of the significant parameters for prediction of rain attenuation for Earth-space telecommunication links, especially those operating at frequencies above 10 GHz. This study examines Three-parameter Dagum distribution of the rain height over Durban, South Africa. 5-year data were used to study the monthly, seasonal, and annual variations using the parameters estimated by the maximum likelihood of the distribution. The performance estimation of the distribution was determined using the statistical goodness of fit. Three-parameter Dagum distribution shows an appropriate distribution for the modeling of rain height over Durban with the Root Mean Square Error of 0.26. Also, the shape and scale parameters for the distribution show a wide variation. The probability exceedance of time for 0.01% indicates the high probability of rain attenuation at higher frequencies.

77 FR 33237 - Saline Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National...

Science.gov (United States)

2012-06-05

... Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National Park, Inyo... an Environmental Impact Statement for the Saline Valley Warm Springs Management Plan, Death Valley... analysis process for the Saline Valley Warm Springs Management Plan for Death Valley [[Page 33238...

Effects of sulfuric, nitric, and mixed acid rain on Chinese fir sapling growth in Southern China.

Science.gov (United States)

Liu, Xin; Fu, Zhiyuan; Zhang, Bo; Zhai, Lu; Meng, Miaojing; Lin, Jie; Zhuang, Jiayao; Wang, G Geoff; Zhang, Jinchi

2018-05-23

The influence of acid rain on plant growth includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in root growth. In addition, the concentration of NO 3 - in acid rain increases along with the rapid growth of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO 4 2- /NO 3 - (S/N) ratios, which were 1:0, 5:1, 1:1, 1:5 and 0:1, on Chinese fir sapling growth from March 2015 to April 2016. Results showed that Chinese fir sapling height growth rate (HGR) and basal diameter growth rate (DGR) decreased as acid rain pH decreased, and also decreased as the percentage of NO 3 - increased in acid rain. Acid rain pH significantly decreased the Chlorophyll a (Chla) and Chlorophyll b (Chlb) content, and Chla and Chlb contents with acid rain S/N 1:5 were significantly lower than those with S/N 1:0 at pH 2.5. The chlorophyll fluorescence parameters, maximal efficiency of Photosystem II photochemistry (Fv/Fm) and non-photochemical quenching coefficient (NPQ), with most acid rain treatments were significantly lower than those with CK treatments. Root activities first increased and then decreased as acid rain pH decreased, when acid rain S/N ratios were 1:1, 1:5 and 0:1. Redundancy discriminant analysis (RDA) showed that the Chinese fir DGR and HGR had positive correlations with Chla, Chlb, Fv/Fm ratio, root activity, catalase and superoxide dismutase activities in roots under the stress of acid rain with different pH and S/N ratios. The structural equation modelling (SEM) results showed that acid rain NO 3 - concentration and pH had stronger direct effects on Chinese fir sapling HGR and DGR, and the direct effects of acid rain NO 3 - concentration and pH on HGR were lower than those on DGR. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect the sustainable development of monoculture Chinese fir plantations in southern China

Nonlinear response in runoff magnitude to fluctuating rain patterns.

Science.gov (United States)

Curtu, R; Fonley, M

2015-03-01

The runoff coefficient of a hillslope is a reliable measure for changes in the streamflow response at the river link outlet. A high runoff coefficient is a good indicator of the possibility of flash floods. Although the relationship between runoff coefficient and streamflow has been the subject of much study, the physical mechanisms affecting runoff coefficient including the dependence on precipitation pattern remain open topics for investigation. In this paper, we analyze a rainfall-runoff model at the hillslope scale as that hillslope is forced with different rain patterns: constant rain and fluctuating rain with different frequencies and amplitudes. When an oscillatory precipitation pattern is applied, although the same amount of water may enter the system, its response (measured by the runoff coefficient) will be maximum for a certain frequency of precipitation. The significant increase in runoff coefficient after a certain pattern of rainfall can be a potential explanation for the conditions preceding flash-floods.

Seasonal rhythms of seed rain and seedling emergence in two tropical rain forests in southern Brazil.

Science.gov (United States)

Marques, M C M; Oliveira, P E A M

2008-09-01

Seasonal tropical forests show rhythms in reproductive activities due to water stress during dry seasons. If both seed dispersal and seed germination occur in the best environmental conditions, mortality will be minimised and forest regeneration will occur. To evaluate whether non-seasonal forests also show rhythms, for 2 years we studied the seed rain and seedling emergence in two sandy coastal forests (flooded and unflooded) in southern Brazil. In each forest, one 100 x 30-m grid was marked and inside it 30 stations comprising two seed traps (0.5 x 0.5 m each) and one plot (2 x 2 m) were established for monthly monitoring of seed rain and a seedling emergence study, respectively. Despite differences in soil moisture and incident light on the understorey, flooded and unflooded forests had similar dispersal and germination patterns. Seed rain was seasonal and bimodal (peaks at the end of the wetter season and in the less wet season) and seedling emergence was seasonal and unimodal (peaking in the wetter season). Approximately 57% of the total species number had seedling emergence 4 or more months after dispersal. Therefore, both seed dormancy and the timing of seed dispersal drive the rhythm of seedling emergence in these forests. The peak in germination occurs in the wetter season, when soil fertility is higher and other phenological events also occur. The strong seasonality in these plant communities, even in this weakly seasonal climate, suggests that factors such as daylength, plant sensitivity to small changes in the environment (e.g. water and nutrient availability) or phylogenetic constraints cause seasonal rhythms in the plants.

Modelling the embedded rainfall process using tipping bucket data

DEFF Research Database (Denmark)

Thyregod, Peter; Arnbjerg-Nielsen, Karsten; Madsen, Henrik

1998-01-01

A new method for modelling the dynamics of rain measurement processes is suggested. The method takes the discrete nature and autocorrelation of measurements from the tipping bucket rain gauge into consideration. The considered model is a state space model with a Poisson marginal distribution....... In the model there is only one parameter, a thinning parameter. The model is tested on 39 rain events. The estimated value for the various rain events is reflecting a subjective classification of rain events into frontal and convective rain. Finally, it is demonstrated how the model can be used for simulation...

The Effect of Rain-Fed and Supplementary Irrigation on the Yield ...

African Journals Online (AJOL)

The effect of rain-fed with rain-fed supplementary irrigation on yield and yield components of Maize (Zea mays L.) was carried out at Mekelle University main campus under Tigray region in Ethiopia. The experiment was laid out in a Randomized Complete Block Design (RCBD), and investigated in the early cropping season ...

The Role of Ecologists in Designing Rain Gardens: Enhancing Nitrate removal Performance

Science.gov (United States)

Rain gardens are vegetated surface depressions designed to receive stormwater runoff from roads, roofs, and parking lots. Stormwater infiltration through rain gardens’ sandy soils is intended to have both water quantity and quality benefits, through stream peak flow reduction and...

Satellite passive microwave rain rate measurement over croplands during spring, summer and fall

International Nuclear Information System (INIS)

Spencer, R.W.

1984-01-01

Rain rate algorithms for spring, summer and fall that have been developed from comparisons between the brightness temperatures measured by the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) and rain rates derived from operational WSR-57 radars over land are described. Data were utilized from a total of 25 SMMR passes and 234 radars, resulting in ∼12 000 observations of ∼1600 km 2 areas. Multiple correlation coefficients of 0.63, 0.80 and 0.75 are achieved for the spring, summer and fall algorithms, respectively. Most of this information is in the form of multifrequency contrast in brightness temperature, which is interpreted as a measurement of the degree to which the land-emitted radiation is attenuated by the rain systems. The SMMR 37 GHz channel has more information on rain rate than any other channel. By combining the lower frequency channels with the 37 GHz observations, variations in land and precipitation thermometric temperatures can be removed, leaving rain attenuation as the major effect on brightness temperature. Polarization screening at 37 GHz is found to be sufficient to screen out cases of wet ground, which is only important when the ground is relatively vegetation free. Heavy rain cases are found to be a significant part of the algorithms' success, because of the strong microwave signatures (low brightness temperatures) that result from the presence of precipitation-sized ice in the upper portions of heavily precipitating storms. If IR data are combined with the summer microwave data, an improved (0.85) correlation with radar rain rates is achieved

Combined MW-IR Precipitation Evolving Technique (PET of convective rain fields

Directory of Open Access Journals (Sweden)

F. Di Paola

2012-11-01

Full Text Available This paper describes a new multi-sensor approach for convective rain cell continuous monitoring based on rainfall derived from Passive Microwave (PM remote sensing from the Low Earth Orbit (LEO satellite coupled with Infrared (IR remote sensing Brightness Temperature (TB from the Geosynchronous (GEO orbit satellite. The proposed technique, which we call Precipitation Evolving Technique (PET, propagates forward in time and space the last available rain-rate (RR maps derived from Advanced Microwave Sounding Units (AMSU and Microwave Humidity Sounder (MHS observations by using IR TB maps of water vapor (6.2 μm and thermal-IR (10.8 μm channels from a Spinning Enhanced Visible and Infrared Imager (SEVIRI radiometer. PET is based on two different modules, the first for morphing and tracking rain cells and the second for dynamic calibration IR-RR. The Morphing module uses two consecutive IR data to identify the motion vector to be applied to the rain field so as to propagate it in time and space, whilst the Calibration module computes the dynamic relationship between IR and RR in order to take into account genesis, extinction or size variation of rain cells. Finally, a combination of the Morphing and Calibration output provides a rainfall map at IR space and time scale, and the whole procedure is reiterated by using the last RR map output until a new MW-based rainfall is available. The PET results have been analyzed with respect to two different PM-RR retrieval algorithms for seven case studies referring to different rainfall convective events. The qualitative, dichotomous and continuous assessments show an overall ability of this technique to propagate rain field at least for 2–3 h propagation time.

Rain concentration and sheltering effect of solar panels on cultivated plots

Science.gov (United States)

Elamri, Yassin; Cheviron, Bruno; Mange, Annabelle; Dejean, Cyril; Liron, François; Belaud, Gilles

2018-02-01

Agrivoltaism is the association of agricultural and photovoltaic energy production on the same land area, coping with the increasing pressure on land use and water resources while delivering clean and renewable energy. However, the solar panels located above the cultivated plots also have a seemingly yes unexplored effect on rain redistribution, sheltering large parts of the plot but redirecting concentrated fluxes on a few locations. The spatial heterogeneity in water amounts observed on the ground is high in the general case; its dynamical patterns are directly attributable to the mobile panels through their geometrical characteristics (dimensions, height, coverage percentage) and the strategies selected to rotate them around their support tube. A coefficient of variation is used to measure this spatial heterogeneity and to compare it with the coefficient of uniformity that classically describes the efficiency of irrigation systems. A rain redistribution model (AVrain) was derived from literature elements and theoretical grounds and then validated from experiments in both field and controlled conditions. AVrain simulates the effective rain amounts on the plot from a few forcing data (rainfall, wind velocity and direction) and thus allows real-time strategies that consist in operating the panels so as to limit the rain interception mainly responsible for the spatial heterogeneities. Such avoidance strategies resulted in a sharp decrease in the coefficient of variation, e.g. 0.22 vs. 2.13 for panels held flat during one of the monitored rain events, which is a fairly good uniformity score for irrigation specialists. Finally, the water amounts predicted by AVrain were used as inputs to Hydrus-2D for a brief exploratory study on the impact of the presence of solar panels on rain redistribution at shallow depths within soils: similar, more diffuse patterns were simulated and were coherent with field measurements.

Active Movement Warm-Up Routines

Science.gov (United States)

Walter, Teri; Quint, Ashleigh; Fischer, Kim; Kiger, Joy

2011-01-01

This article presents warm-ups that are designed to physiologically and psychologically prepare students for vigorous physical activity. An active movement warm-up routine is made up of three parts: (1) active warm-up movement exercises, (2) general preparation, and (3) the energy system. These warm-up routines can be used with all grade levels…

Compensatory mechanisms mitigate the effect of warming and drought on wood formation.

Science.gov (United States)

Balducci, Lorena; Cuny, Henri E; Rathgeber, Cyrille B K; Deslauriers, Annie; Giovannelli, Alessio; Rossi, Sergio

2016-06-01

Because of global warming, high-latitude ecosystems are expected to experience increases in temperature and drought events. Wood formation will have to adjust to these new climatic constraints to maintain tree mechanical stability and long-distance water transport. The aim of this study is to understand the dynamic processes involved in wood formation under warming and drought. Xylogenesis, gas exchange, water relations and wood anatomy of black spruce [Picea mariana (Mill.) B.S.P.] saplings were monitored during a greenhouse experiment where temperature was increased during daytime or night-time (+6 °C) combined with a drought period. The kinetics of tracheid development expressed as rate and duration of the xylogenesis sub-processes were quantified using generalized additive models. Drought and warming had a strong influence on cell production, but little effect on wood anatomy. The increase in cell production rate under warmer temperatures, and especially during the night-time warming at the end of the growing season, resulted in wider tree-rings. However, the strong compensation between rates and durations of cell differentiation processes mitigates warming and drought effects on tree-ring structure. Our results allowed quantification of how wood formation kinetics is regulated when water and heat stress increase, allowing trees to adapt to future environmental conditions. © 2015 John Wiley & Sons Ltd.

Multi-scale responses to warming in an experimental insect metacommunity.

Science.gov (United States)

Grainger, Tess Nahanni; Gilbert, Benjamin

2017-12-01

In metacommunities, diversity is the product of species interactions at the local scale and dispersal between habitat patches at the regional scale. Although warming can alter both species interactions and dispersal, the combined effects of warming on these two processes remains uncertain. To determine the independent and interactive effects of warming-induced changes to local species interactions and dispersal, we constructed experimental metacommunities consisting of enclosed milkweed patches seeded with five herbivorous milkweed specialist insect species. We treated metacommunities with two levels of warming (unwarmed and warmed) and three levels of connectivity (isolated, low connectivity, high connectivity). Based on metabolic theory, we predicted that if plant resources were limited, warming would accelerate resource drawdown, causing local insect declines and increasing both insect dispersal and the importance of connectivity to neighboring patches for insect persistence. Conversely, given abundant resources, warming could have positive local effects on insects, and the risk of traversing a corridor to reach a neighboring patch could outweigh the benefits of additional resources. We found support for the latter scenario. Neither resource drawdown nor the weak insect-insect associations in our system were affected by warming, and most insect species did better locally in warmed conditions and had dispersal responses that were unchanged or indirectly affected by warming. Dispersal across the matrix posed a species-specific risk that led to declines in two species in connected metacommunities. Combined, this scaled up to cause an interactive effect of warming and connectivity on diversity, with unwarmed metacommunities with low connectivity incurring the most rapid declines in diversity. Overall, this study demonstrates the importance of integrating the complex outcomes of species interactions and spatial structure in understanding community response to climate

Rain rate measurements over global oceans from IRS-P4 MSMR

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

This algorithm explained about 82 per cent correlation (r) with rain rate, and 1.61 mm h−1 of error of estimation. ... MSMR derived monthly averaged rain rates are compared with similar estimates from. TRMM Precipitation Radar (PR), and it .... A second order polynomial fit explains corre- lation for 10 GHz vertically polarized ...

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

Science.gov (United States)

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

Soak Up the Rain Customizable Outreach Tools

Science.gov (United States)

Get customizable Soak Up the Rain business card, posters, & a banner that can be downloaded & copied for use by citizens, municipalities, watershed & planning organizations & others in their stormwater/green infrastructure education & outreach efforts.

Comparing Satellite Rainfall Estimates with Rain-Gauge Data: Optimal Strategies Suggested by a Spectral Model

Science.gov (United States)

Bell, Thomas L.; Kundu, Prasun K.; Lau, William K. M. (Technical Monitor)

2002-01-01

Validation of satellite remote-sensing methods for estimating rainfall against rain-gauge data is attractive because of the direct nature of the rain-gauge measurements. Comparisons of satellite estimates to rain-gauge data are difficult, however, because of the extreme variability of rain and the fact that satellites view large areas over a short time while rain gauges monitor small areas continuously. In this paper, a statistical model of rainfall variability developed for studies of sampling error in averages of satellite data is used to examine the impact of spatial and temporal averaging of satellite and gauge data on intercomparison results. The model parameters were derived from radar observations of rain, but the model appears to capture many of the characteristics of rain-gauge data as well. The model predicts that many months of data from areas containing a few gauges are required to validate satellite estimates over the areas, and that the areas should be of the order of several hundred km in diameter. Over gauge arrays of sufficiently high density, the optimal areas and averaging times are reduced. The possibility of using time-weighted averages of gauge data is explored.

The urban perspectives of acid rain

International Nuclear Information System (INIS)

Tonn, B.E.

1993-01-01

This report documents discussions held during a workshop an Urban Perspective of Acid Rain. The workshop was sponsored by the Office of the Director, National Acid Precipitation Assessment Program (NAPAP). NAPAP anticipates giving increased emphasis to the benefits in urban areas of emissions reductions. The goal of this informal, exploratory workshop was to serve as a first step towards identifying pollutant monitoring, and research and assessment needs to help answer, from an urban perspective, the two key questions posed to NAPAP by Congress: (1) what are the costs, benefits, and effectiveness of the acid rain control program, and (2) what reductions in deposition, rates are needed in order to prevent adverse effects? The workshop addressed research activities needed to respond to these questions. The discussions focused. sequentially, on data needs, data and model availability, and data and modeling gaps. The discussions concentrated on four areas of effects: human health, materials, urban forests, and visibility

Radiation-dose consequences of acid rain

International Nuclear Information System (INIS)

Sheppard, S.C.; Sheppard, M.I.; Mitchell, J.H.

1987-01-01

Acid rain causes accelerated mobilization of many materials in soils. Natural and anthropogenic radionuclides, especially Ra and Cs, are among these materials. Generally, a decrease in soil pH by 1 unit will cause increases in mobility and plant uptake by factors of 2 to 7. Several simulation models were tested with most emphasis on an atmospherically driven soil model that predicts water and nuclide flow through a soil profile. We modelled a typical, acid rain sensitive soil using meterological data from Geraldton, Ontario. The results, within the range of effects on the soil expected from acidification, showed direct proportionality between the mobility of the nuclides and dose. Based on the literature available, a decrease in pH of 1 unit may increase the mobility of Ra and Cs by a factor or 2 or more. This will lead to increases in plant uptake and ultimate dose to man of about the same extent

Development and Performance Evaluation of a Rain Shade for a low ...

African Journals Online (AJOL)

Aderoju Tomiwa

for a low scale agricultural produce, The rain shade consists of a geared D. C motor, 12V battery, ... rain shade was embarked on in this research work. ... (9) Face width, b. +. 5mm (10). Determination of weight acting on the Extension. Arm: The measured weight of the polyester fabric equals 14.7N, while the combined ...

Weakening of the North American monsoon with global warming

Science.gov (United States)

Pascale, Salvatore; Boos, William R.; Bordoni, Simona; Delworth, Thomas L.; Kapnick, Sarah B.; Murakami, Hiroyuki; Vecchi, Gabriel A.; Zhang, Wei

2017-11-01

Future changes in the North American monsoon, a circulation system that brings abundant summer rains to vast areas of the North American Southwest, could have significant consequences for regional water resources. How this monsoon will change with increasing greenhouse gases, however, remains unclear, not least because coarse horizontal resolution and systematic sea-surface temperature biases limit the reliability of its numerical model simulations. Here we investigate the monsoon response to increased atmospheric carbon dioxide (CO2) concentrations using a 50-km-resolution global climate model which features a realistic representation of the monsoon climatology and its synoptic-scale variability. It is found that the monsoon response to CO2 doubling is sensitive to sea-surface temperature biases. When minimizing these biases, the model projects a robust reduction in monsoonal precipitation over the southwestern United States, contrasting with previous multi-model assessments. Most of this precipitation decline can be attributed to increased atmospheric stability, and hence weakened convection, caused by uniform sea-surface warming. These results suggest improved adaptation measures, particularly water resource planning, will be required to cope with projected reductions in monsoon rainfall in the American Southwest.

Nanoscale study on water damage for different warm mix asphalt binders

Directory of Open Access Journals (Sweden)

Kefei Liu

2016-11-01

Full Text Available In order to analyze the water damage to different warm mix asphalt binders from the micro scale, five kinds of asphalt binders, 70#A base asphalt, sasobit warm mix asphalt, energy champion 120 °C (EC120 warm mix asphalt, aspha-min warm mix asphalt, sulfur-extended asphalt modifier (SEAM warm mix asphalt, under different conditions (dry/wet, original/aging are prepared for laboratory tests. The atomic force microscope (AFM is used to observe the surface properties and measure the adhesion force between the asphalt and the mineral aggregate. The obtained results show that under the dry condition aspha-min warm mix asphalt and SEAM warm mix asphalt show stronger adhesive ability with the mineral aggregate compared with other asphalt binders, but also have relatively large dispersion and fluctuation in the tested results; under the wet condition, aspha-min warm mix asphalt and SEAM warm mix asphalt show stronger water damage resistance ability. The EC120 warm mix asphalt and aspha-min warm mix asphalt are less sensitive to moist, and their corresponding adhesion force is less susceptible to the change of external moisture conditions, leading to a better ability to resist water erosion. The aging process significantly lowers the moisture erosion resistance ability, which further impairs the water damage resistance ability. The base asphalt is more sensitive to moisture and more vulnerable to water damage, no matter whether it is under original or aging conditions. The aging aspha-min warm mix asphalt has the least loss of adhesion force, the smallest dispersion of the tested adhesion force, the strongest water damage resistance ability, no matter it is dry or wet. Keywords: Road engineering, Warm mix asphalt, Moisture damage, Atomic force microscope, Microcosmic

Respiration rates in forest soil organic horizon materials treated with simulated acid rain

Energy Technology Data Exchange (ETDEWEB)

Salonius, P O

1990-01-01

The entire organic horizon above the mineral soil was collected under a mature black spruce (Picea mariana) stand in central New Brunswick. The organic horizon consisted of litter, fermentation, and humus layers of 1.5, 4.0, and 1.0 cm depths respectively. In concert with a series of simulated rain experiments, which dealt with the effects of acid precipitation of pH 4.6, 3.6, and 2.6 compared with controls at pH 5.6 on germination and early growth of forest tree seedlings, 30 randomly distributed, unplanted tubes in each rain chamber were exposed to treatment during each of the 5-week treatments of the various tree species. During the experiments, ca 315 mm of simulated rain was deposited on the soil surfaces in the tube containers. Marked decreases in soil microbial activity were found only with pH 2.6 rain, but responsiveness to increasing temperature was lower as rain of greater acidity was applied to the soil. Ammonium nitrogen mineralization rates were not affected by treatment of soil with acidified precipitation. 26 refs., 3 figs., 1 tab.

Haloacetates in fog and rain.

Science.gov (United States)

Römpp, A; Klemm, O; Fricke, W; Frank, H

2001-04-01

Atmospheric haloacetates can arise from photochemical degradation of halogenated hydrocarbons and from direct anthropogenic emissions. Furthermore, there is also evidence of natural sources although these are quantitatively uncertain. As haloacetates are highly soluble in water, hydrometeors are most significant for their deposition. Fogwater (96 samples) and rainwater samples (over 100 samples) were collected from July 1998 to March 1999 at an ecological research site in northeastern Bavaria, Germany. They were analyzed for monofluoroacetate (MFA), difluoroacetate (DFA), trifluoroacetate (TFA), monochloroacetate (MCA), dichloroacetate (DCA), trichloroacetate (TCA), monobromoacetate (MBA), and dibromoacetate (DBA). The major inorganic ions were also determined. High concentrations of up to 11 microg/L MCA, 5 microg/L DCA, 2 microg/L TCA, and 2 microg/L TFA were found in fogwater associated with westerly winds. Backward trajectories were calculated to determine the origin of the air masses. MBA and DBA have highest concentrations in fogwater advected with air originating from the Atlantic, suggesting the marine origin of these two compounds. All analyzed substances show higher average concentrations in fog than in rain. Estimates of the deposition of haloacetates suggest that the contribution of fog may be more important than rain for the total burden of a forest ecosystem.

Combating bad weather part I rain removal from video

CERN Document Server

Mukhopadhyay, Sudipta

2015-01-01

Current vision systems are designed to perform in normal weather condition. However, no one can escape from severe weather conditions. Bad weather reduces scene contrast and visibility, which results in degradation in the performance of various computer vision algorithms such as object tracking, segmentation and recognition. Thus, current vision systems must include some mechanisms that enable them to perform up to the mark in bad weather conditions such as rain and fog. Rain causes the spatial and temporal intensity variations in images or video frames. These intensity changes are due to the

STATE ACID RAIN RESEARCH AND SCREENING SYSTEM - VERSION 1.0 USER'S MANUAL

Science.gov (United States)

The report is a user's manual that describes Version 1.0 of EPA's STate Acid Rain Research and Screening System (STARRSS), developed to assist utility regulatory commissions in reviewing utility acid rain compliance plans. It is a screening tool that is based on scenario analysis...

BIOGEOGRAPHICAL IMPLICATIONS OF SOME PLANT SPECIES FROM A TROPICAL MONTANE RAIN FOREST IN SOUTHERN YUNNAN

Institute of Scientific and Technical Information of China (English)

ZHU Hua

2004-01-01

A pristine montane rain forest was recently discovered from Mengsong of Xishuangbanna in the southern Yunnan.It attracts botanists that many primitive plant taxa across various life forms were co-existed in the montane rain forest.In order to know the biogeography of the montane rain forest,distribution patterns of some species of biogeographical importance from the montane forest were enumerated and their biogeographical implications were discussed with geological explanation.It was concluded that the montane rain forest in the southern Yunnan has strong affinity to montane rain forests in Sumatra or Southeast Asia in broad sense.It was tentatively suggested that Sumatra could be once connected to Myanmar and drifted away due to northward movement of continental Asia by bumping of India plate.

URBAN RAIN GAUGE SITING SELECTION BASED ON GIS-MULTICRITERIA ANALYSIS

OpenAIRE

Y. Fu; C. Jing; M. Du

2016-01-01

With the increasingly rapid growth of urbanization and climate change, urban rainfall monitoring as well as urban waterlogging has widely been paid attention. In the light of conventional siting selection methods do not take into consideration of geographic surroundings and spatial-temporal scale for the urban rain gauge site selection, this paper primarily aims at finding the appropriate siting selection rules and methods for rain gauge in urban area. Additionally, for optimization gauge loc...

Warm Mix Asphalt

Science.gov (United States)

2009-04-17

State of Alaska State of Alaska - Warm Mix Project Warm Mix Project: Location - Petersburg, Alaska which is Petersburg, Alaska which is located in the heart of Southeast Alaska located in the heart of Southeast Alaska's Inside Passage at the tip of M...

[Effects of simulated acid rain on Quercus glauca seedlings photosynthesis and chlorophyll fluorescence].

Science.gov (United States)

Li, Jia; Jiang, Hong; Yu, Shu-quan; Jiang, Fu-wei; Yin, Xiu-min; Lu, Mei-juan

2009-09-01

Taking the seedlings of Quercus glauca, a dominant evergreen broadleaf tree species in subtropical area, as test materials, this paper studied their photosynthesis, chlorophyll fluorescence, and chlorophyll content under effects of simulated acid rain with pH 2.5, 4.0, and 5.6 (CK). After 2-year acid rain stress, the net photosynthetic rate of Q. glauca increased significantly with decreasing pH of acid rain. The acid rain with pH 2.5 and 4.0 increased the stomatal conductance and transpiration rate, and the effect was more significant under pH 2.5. The intercellular CO2 concentration decreased in the order of pH 2.5 > pH 5.6 > pH 4.0. The maximum photosynthetic rate, light compensation point, light saturation point, and dark respiration rate were significantly higher under pH 2.5 and 4.0 than under pH 5.6, while the apparent quantum yield was not sensitive to acid rain stress. The maximal photochemical efficiency of PS II and the potential activity of PS II under pH 2.5 and 4.0 were significantly higher than those under pH 5.6. The relative chlorophyll content was in the order of pH 2.5 > pH 5.6 > pH 4.0, and there was a significant difference between pH 2.5 and 4.0. All the results suggested that the photosynthesis and chlorophyll fluorescence of Q. glauca increased under the effects of acid rain with pH 2.5 and 4.0, and the acid rain with pH 2.5 had more obvious effects.

PSYCHOLINGUISTIC CHARACTERISTICS OF AUTISTS AND THEIR PROTOTYPES IN AMERICAN CINEMA DISCOURSE (BASED ON THE FILMS RAIN MAN AND THE REAL RAIN MAN

Directory of Open Access Journals (Sweden)

L.M. Ikalyuk

2015-09-01

Full Text Available The article focuses on the study of the main characteristics of people with autistic spectrum disorders. The comparison between the famous American savant, Kim Peek, and his prototype in the American cinema discourse has been made on the basis of the films Rain Man and The Real Rain Man. With the help of psychographological analysis, the speech of the man and his fictional prototype has been examined. The analysis showed that the difference between the two persons is indubitable, which can be explained by the fact that the savant syndrome was caused by different disorders.

Multi-grid Beam and Warming scheme for the simulation of unsteady ...

African Journals Online (AJOL)

In this paper, a multi-grid algorithm is applied to a large-scale block matrix that is produced from a Beam and Warming scheme. The Beam and Warming scheme is used in the simulation of unsteady flow in an open channel. The Gauss-Seidel block-wise iteration method is used for a smoothing process with a few iterations.

AMSR-E/Aqua L2B Global Swath Rain Rate/Type GSFC Profiling Algorithm V002

Data.gov (United States)

National Aeronautics and Space Administration — The AMSR-E/Aqua Level-2B rain product includes instantaneous rain rate and rain type over ice-free and snow-free land and ocean between 70 degrees north and south...

Scaling properties of Polish rain series

Science.gov (United States)

Licznar, P.

2009-04-01

Scaling properties as well as multifractal nature of precipitation time series have not been studied for local Polish conditions until recently due to lack of long series of high-resolution data. The first Polish study of precipitation time series scaling phenomena was made on the base of pluviograph data from the Wroclaw University of Environmental and Life Sciences meteorological station located at the south-western part of the country. The 38 annual rainfall records from years 1962-2004 were converted into digital format and transformed into a standard format of 5-minute time series. The scaling properties and multifractal character of this material were studied by means of several different techniques: power spectral density analysis, functional box-counting, probability distribution/multiple scaling and trace moment methods. The result proved the general scaling character of time series at the range of time scales ranging form 5 minutes up to at least 24 hours. At the same time some characteristic breaks at scaling behavior were recognized. It is believed that the breaks were artificial and arising from the pluviograph rain gauge measuring precision limitations. Especially strong limitations at the precision of low-intensity precipitations recording by pluviograph rain gauge were found to be the main reason for artificial break at energy spectra, as was reported by other authors before. The analysis of co-dimension and moments scaling functions showed the signs of the first-order multifractal phase transition. Such behavior is typical for dressed multifractal processes that are observed by spatial or temporal averaging on scales larger than the inner-scale of those processes. The fractal dimension of rainfall process support derived from codimension and moments scaling functions geometry analysis was found to be 0.45. The same fractal dimension estimated by means of the functional box-counting method was equal to 0.58. At the final part of the study

Rain-harvesting behavior in agamid lizards (Trapelus)

Czech Academy of Sciences Publication Activity Database

Veselý, M.; Modrý, David

2002-01-01

Roč. 36, č. 2 (2002), s. 311-314 ISSN 0022-1511 Institutional research plan: CEZ:AV0Z6022909 Keywords : lizards * ethology * rain-harvesting behavior Subject RIV: EG - Zoology Impact factor: 0.649, year: 2002

Measurement of radioactivity in rain

International Nuclear Information System (INIS)

Eivindson, T.

1985-01-01

The report gives a description of an ion-exchange surveillance- sampler for routine measurements of radioactivity in rain, and how the measurements are performed. Using the nuclides 85 Sr, 131 I and 137 Cs as tracers, experiments have been performed to determine the distribution of radioactivity in the ion-exchange column and the effectiveness of the column as a function of elutriation rate and temperature

A westward extension of the warm pool leads to a westward extension of the Walker circulation, drying eastern Africa

Energy Technology Data Exchange (ETDEWEB)

Williams, A.P.; Funk, Chris [University of California, Santa Barbara, Geography Department, Santa Barbara, CA (United States)

2011-12-15

Observations and simulations link anthropogenic greenhouse and aerosol emissions with rapidly increasing Indian Ocean sea surface temperatures (SSTs). Over the past 60 years, the Indian Ocean warmed two to three times faster than the central tropical Pacific, extending the tropical warm pool to the west by {proportional_to}40 longitude (>4,000 km). This propensity toward rapid warming in the Indian Ocean has been the dominant mode of interannual variability among SSTs throughout the tropical Indian and Pacific Oceans (55 E-140 W) since at least 1948, explaining more variance than anomalies associated with the El Nino-Southern Oscillation (ENSO). In the atmosphere, the primary mode of variability has been a corresponding trend toward greatly increased convection and precipitation over the tropical Indian Ocean. The temperature and rainfall increases in this region have produced a westward extension of the western, ascending branch of the atmospheric Walker circulation. Diabatic heating due to increased mid-tropospheric water vapor condensation elicits a westward atmospheric response that sends an easterly flow of dry air aloft toward eastern Africa. In recent decades (1980-2009), this response has suppressed convection over tropical eastern Africa, decreasing precipitation during the 'long-rains' season of March-June. This trend toward drought contrasts with projections of increased rainfall in eastern Africa and more 'El Nino-like' conditions globally by the Intergovernmental Panel on Climate Change. Increased Indian Ocean SSTs appear likely to continue to strongly modulate the Warm Pool circulation, reducing precipitation in eastern Africa, regardless of whether the projected trend in ENSO is realized. These results have important food security implications, informing agricultural development, environmental conservation, and water resource planning. (orig.)

Warm dense matter and Thomson scattering at FLASH

International Nuclear Information System (INIS)

Faeustlin, Roland Rainer

2010-05-01

X-ray free electron lasers are powerful tools to investigate moderately to strongly correlated solid density low temperature plasmas, named warm dense matter. These plasmas are of most interest for astrophysics and laser plasma interaction, particularly inertial confinement fusion. This work utilizes the ultrashort soft x-ray pulse duration and high brilliance of the free electron laser in Hamburg, FLASH, to generate warm dense matter and to study its ultrafast processes. The techniques applied are absorption measurement, emission spectroscopy and Thomson scattering. Radiative hydrodynamics and Thomson scattering simulations are used to investigate the impact of temperature and density gradients in the sample and to fit the experimental data. The measurements result in a comprehensive picture of soft x-ray matter interaction related to warm dense matter and yield insight into ultrafast equilibration and relaxation mechanisms, in particular impact ionization and radiative recombination. (orig.)

Warm dense matter and Thomson scattering at FLASH

Energy Technology Data Exchange (ETDEWEB)

Faeustlin, Roland Rainer

2010-05-15

X-ray free electron lasers are powerful tools to investigate moderately to strongly correlated solid density low temperature plasmas, named warm dense matter. These plasmas are of most interest for astrophysics and laser plasma interaction, particularly inertial confinement fusion. This work utilizes the ultrashort soft x-ray pulse duration and high brilliance of the free electron laser in Hamburg, FLASH, to generate warm dense matter and to study its ultrafast processes. The techniques applied are absorption measurement, emission spectroscopy and Thomson scattering. Radiative hydrodynamics and Thomson scattering simulations are used to investigate the impact of temperature and density gradients in the sample and to fit the experimental data. The measurements result in a comprehensive picture of soft x-ray matter interaction related to warm dense matter and yield insight into ultrafast equilibration and relaxation mechanisms, in particular impact ionization and radiative recombination. (orig.)

How warm days increase belief in global warming

Science.gov (United States)

Zaval, Lisa; Keenan, Elizabeth A.; Johnson, Eric J.; Weber, Elke U.

2014-02-01

Climate change judgements can depend on whether today seems warmer or colder than usual, termed the local warming effect. Although previous research has demonstrated that this effect occurs, studies have yet to explain why or how temperature abnormalities influence global warming attitudes. A better understanding of the underlying psychology of this effect can help explain the public's reaction to climate change and inform approaches used to communicate the phenomenon. Across five studies, we find evidence of attribute substitution, whereby individuals use less relevant but available information (for example, today's temperature) in place of more diagnostic but less accessible information (for example, global climate change patterns) when making judgements. Moreover, we rule out alternative hypotheses involving climate change labelling and lay mental models. Ultimately, we show that present temperature abnormalities are given undue weight and lead to an overestimation of the frequency of similar past events, thereby increasing belief in and concern for global warming.

Aerosol size-dependent below-cloud scavenging by rain and snow in the ECHAM5-HAM

Directory of Open Access Journals (Sweden)

R. Posselt

2009-07-01

Full Text Available Wet deposition processes are highly efficient in the removal of aerosols from the atmosphere, and thus strongly influence global aerosol concentrations, and clouds, and their respective radiative forcings. In this study, physically detailed size-dependent below-cloud scavenging parameterizations for rain and snow are implemented in the ECHAM5-HAM global aerosol-climate model. Previously, below-cloud scavenging by rain in the ECHAM5-HAM was simply a function of the aerosol mode, and then scaled by the rainfall rate. The below-cloud scavenging by snow was a function of the snowfall rate alone. The global mean aerosol optical depth, and sea salt burden are sensitive to the below-cloud scavenging coefficients, with reductions near to 15% when the more vigorous size-dependent below-cloud scavenging by rain and snow is implemented. The inclusion of a prognostic rain scheme significantly reduces the fractional importance of below-cloud scavenging since there is higher evaporation in the lower troposphere, increasing the global mean sea salt burden by almost 15%. Thermophoretic effects are shown to produce increases in the global and annual mean number removal of Aitken size particles of near to 10%, but very small increases (near 1% in the global mean below-cloud mass scavenging of carbonaceous and sulfate aerosols. Changes in the assumptions about the below-cloud scavenging by rain of particles with radius smaller than 10 nm do not cause any significant changes to the global and annual mean aerosol mass or number burdens, despite a change in the below-cloud number removal rate for nucleation mode particles by near to five-fold. Annual and zonal mean nucleation mode number concentrations are enhanced by up to 30% in the lower troposphere with the more vigourous size-dependent below-cloud scavenging. Closer agreement with different observations is found when the more physically detailed below-cloud scavenging parameterization is employed in the ECHAM5

Non-linear direct effects of acid rain on leaf photosynthetic rate of terrestrial plants.

Science.gov (United States)

Dong, Dan; Du, Enzai; Sun, Zhengzhong; Zeng, Xuetong; de Vries, Wim

2017-12-01

Anthropogenic emissions of acid precursors have enhanced global occurrence of acid rain, especially in East Asia. Acid rain directly suppresses leaf function by eroding surface waxes and cuticle and leaching base cations from mesophyll cells, while the simultaneous foliar uptake of nitrates in rainwater may directly benefit leaf photosynthesis and plant growth, suggesting a non-linear direct effect of acid rain. By synthesizing data from literature on acid rain exposure experiments, we assessed the direct effects of acid rain on leaf photosynthesis across 49 terrestrial plants in China. Our results show a non-linear direct effect of acid rain on leaf photosynthetic rate, including a neutral to positive effect above pH 5.0 and a negative effect below that pH level. The acid rain sensitivity of leaf photosynthesis showed no significant difference between herbs and woody species below pH 5.0, but the impacts above that pH level were strongly different, resulting in a significant increase in leaf photosynthetic rate of woody species and an insignificant effect on herbs. Our analysis also indicates a positive effect of the molar ratio of nitric versus sulfuric acid in the acid solution on leaf photosynthetic rate. These findings imply that rainwater acidity and the composition of acids both affect the response of leaf photosynthesis and therefore result in a non-linear direct effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

Refrigeration and global warming

International Nuclear Information System (INIS)

Anon.

1997-01-01

Some aspects of global warming in general, and the implications for refrigerants and refrigerator efficiency in particular, are briefly considered in a question and answer format. The concepts of Global Warming Potential (GWP) and Total Equivalent Warming Impact (TEWI) are explained. GWP is an index which allows a simple comparison to be make between the warming effects of different gases on a kg to kg basis relative to carbon. The GWP depends both on the lifetime of a substance in the atmosphere and its infra-red absorption capacity. The overall warming effect of operating a refrigeration system for its entire life is measured by its TEWI. Chloroflourocarbons (CFCs) which have been widely used as refrigerants are powerful greenhouse gases with high GWPs. Because of the bank of CFCs in refrigerating systems, their levels in the atmosphere are still increasing and it will be some time before refrigerant changes will be effective in reducing the warming effects of refrigerant releases. Hydrocarbons, hydroflourocarbons and ammonia all have a part to play as substitute refrigerants. Refrigerator efficiency is very important in terms of reducing CO 2 emissions. (UK)

GPM GROUND VALIDATION NASA MICRO RAIN RADAR (MRR) MC3E V1

Data.gov (United States)

National Aeronautics and Space Administration — The GPM Ground Validation NASA Micro Rain Radar (MRR) MC3E dataset was collected by a Micro Rain Radar (MRR), which is a vertically pointing Doppler radar which...

The portfolio risk management and diversification benefits from the South African rand currency index (rain

Directory of Open Access Journals (Sweden)

F.Y. Jordaan

2012-12-01

Full Text Available This study attempts to explain the source of risk management and diversification benefits that investors may gain from the South African Rand Currency Index (RAIN as it relates to an equity portfolio with stock market exposure (locally or international. These diversification benefits may result from the negative correlation between RAIN and the South African All Share Index (ALSI. To explain and fully exploit the benefits of RAIN, the main variables that represent South Africa’s trading partner equity and bond markets movements, were identified. To account for the interaction of RAIN with the ALSI, the latter was firstly decomposed into its economic groups and secondly into its various sub-sectors. Various analyses were carried out to determine which variables describe the relationship between the ALSI and RAIN. The variables that describe the relationship with a high adjusted R2, were identified. The findings suggest that when the ALSI is decomposed into its ten economic groups and thirty-seven sub-groups, the quadratic as opposed to linear models using response surface regressions, explained the majority of the variation in RAIN over the entire period. The linear models, however, explained more of the variation in RAIN during the recent 2008/2009 financial crisis

Sea surface freshening inferred from SMOS and ARGO salinity: impact of rain

Directory of Open Access Journals (Sweden)

J. Boutin

2013-02-01

Full Text Available The sea surface salinity (SSS measured from space by the Soil Moisture and Ocean Salinity (SMOS mission has recently been revisited by the European Space Agency first campaign reprocessing. We show that, with respect to the previous version, biases close to land and ice greatly decrease. The accuracy of SMOS SSS averaged over 10 days, 100 × 100 km² in the open ocean and estimated by comparison to ARGO (Array for Real-Time Geostrophic Oceanography SSS is on the order of 0.3–0.4 in tropical and subtropical regions and 0.5 in a cold region. The averaged negative SSS bias (−0.1 observed in the tropical Pacific Ocean between 5° N and 15° N, relatively to other regions, is suppressed when SMOS observations concomitant with rain events, as detected from SSM/Is (Special Sensor Microwave Imager rain rates, are removed from the SMOS–ARGO comparisons. The SMOS freshening is linearly correlated to SSM/Is rain rate with a slope estimated to −0.14 mm⁻¹ h, after correction for rain atmospheric contribution. This tendency is the signature of the temporal SSS variability between the time of SMOS and ARGO measurements linked to rain variability and of the vertical salinity stratification between the first centimeter of the sea surface layer sampled by SMOS and the 5 m depth sampled by ARGO. However, given that the whole set of collocations includes situations with ARGO measurements concomitant with rain events collocated with SMOS measurements under no rain, the mean −0.1 bias and the negative skewness of the statistical distribution of SMOS minus ARGO SSS difference are very likely the mean signature of the vertical salinity stratification. In the future, the analysis of ongoing in situ salinity measurements in the top 50 cm of the sea surface and of Aquarius satellite SSS are expected to provide complementary information about the sea surface salinity stratification.

Effect of salt on color and warmed over flavor in charqui meat processing

Directory of Open Access Journals (Sweden)

Youssef Elza Y.

2003-01-01

Full Text Available A combination of salt (NaCl high concentration and curing salt was investigated for their role in warmed-over flavor (WOF and color changes during charqui meats processing. WOF was measured by TBARS method in uncured charqui meat (CH and in cured charqui known in Brazil as Jerked beef (JB. WOF occurred substantially in CH and sodium nitrite was able to inhibit 40-45% (p<0.05 in JB samples stored for 30 days. Color parameters also changed as evaluated by CIELAB system. The a*/b* ratio showed that CH samples presented brown color indicating the formation of metmyoglobin (Fe3+ whilst JB samples presented deep red color an indication of nitrosylmyoglobin (Fe2+ formation. Under cooking, a*/b* ratio indicated the presence of denatured metmyoglobin (Fe3+ in CH and formation of nitrosylmyochromogen (Fe2+ in JB samples. The actual iron state influenced the color of charqui meat and apparently nitrite was able to chelate Fe ions, thus inhibiting development of WOF.

Acid Rain: A Resource Guide for Classroom, Laboratory, Field, and Debate Topics.

Science.gov (United States)

Stoss, Frederick W.

1987-01-01

Provides a partially annotated bibliography of journals and book chapters which deal with acid rain. Includes selections which provide background information, ideas for introducing acid rain into science or social studies curricula, inventories of audio-visual aids, and non-print media to supplement classroom, laboratory, and field instruction.…

Habitats at Risk. Global Warming and Species Loss in Globally Significant Terrestrial Ecosystems

International Nuclear Information System (INIS)

Malcolm, J.R.; Liu, Canran; Miller, L.B.; Allnutt, T.; Hansen, L.

2002-02-01

In this study, a suite of models of global climate and vegetation change is used to investigate three important global warming-induced threats to the terrestrial Global 200 ecoregions: (1) Invasions by new habitat types (and corresponding loss of original habitat types); (2) Local changes of habitat types; (3) High rates of required species migration. Seven climate models (general circulation models or GCMs) and two vegetation models (BIOME3 and MAPSS) were used to produce 14 impact scenarios under the climate associated with a doubling of atmospheric CO2 concentrations, which is expected to occur in less than 100 years. Previous analyses indicated that most of the variation among the impact scenarios was attributable to the particular vegetation model used, hence the authors provide results separately for the two models. The models do not provide information on biodiversity per se, but instead simulate current and future potential distributions of major vegetation types (biomes) such as tundra and broadleaf tropical rain forest

The climatic scenario of global warming

International Nuclear Information System (INIS)

Deque, M.

2007-01-01

This presentation shows how the ARPEGE model, which is the regional model of Meteo-France, responds to the forcing results of the A2 scenario of the GIEC for the parameters of temperature and rainfalls. It emerges from the study that the main impact in France of the climatic change is an increase of the temperature in all seasons, an increase of the rains in winter and a decrease of the rains in summer. (A.L.B.)

Atmospheric deposition of 7Be by rain events, incentral Argentina

Science.gov (United States)

Ayub, J. Juri; Di Gregorio, D. E.; Huck, H.; Velasco, H.; Rizzotto, M.

2008-08-01

Beryllium-7 is a natural radionuclide that enters into the ecosystems through wet and dry depositions and has numerous environmental applications in terrestrial and aquatic ecosystems. Atmospheric wet deposition of 7Be was measured in central Argentina. Rain traps were installed (1 m above ground) and individual rain events have been collected. Rain samples were filtered and analyzed by gamma spectrometry. The gamma counting was undertaken using a 40%-efficient p-type coaxial intrinsic high-purity natural germanium crystal built by Princeton Gamma-Tech. The cryostat was made from electroformed high-purity copper using ultralow-background technology. The detector was surrounded by 50 cm of lead bricks to provide shielding against radioactive background. The detector gamma efficiency was determined using a water solution with known amounts of chemical compounds containing long-lived naturally occurring radioisotopes, 176Lu, 138La and 40K. Due to the geometry of the sample and its position close to the detector, the efficiency points from the 176Lu decay, had to be corrected for summing effects. The measured samples were 400 ml in size and were counted curing one day. The 7Be detection limit for the present measurements was as low as 0.2 Bq l-1. Thirty two rain events were sampled and analyzed (November 2006-May 2007). The measured values show that the events corresponding to low rainfall (<20 mm) are characterized by significantly higher activity concentrations (Bq l-1). The activity concentration of each individual event varied from 0.8 to 3.5 Bq l-1, while precipitations varied between 4 and 70 mm. The integrated activity by event of 7Be was fitted with a model that takes into account the precipitation amount and the elapsed time between two rain events. The integrated activities calculated with this model show a good agreement with experimental values.

Combining Passive Microwave Rain Rate Retrieval with Visible and Infrared Cloud Classification.

Science.gov (United States)

Miller, Shawn William

The relation between cloud type and rain rate has been investigated here from different approaches. Previous studies and intercomparisons have indicated that no single passive microwave rain rate algorithm is an optimal choice for all types of precipitating systems. Motivated by the upcoming Tropical Rainfall Measuring Mission (TRMM), an algorithm which combines visible and infrared cloud classification with passive microwave rain rate estimation was developed and analyzed in a preliminary manner using data from the Tropical Ocean Global Atmosphere-Coupled Ocean Atmosphere Response Experiment (TOGA-COARE). Overall correlation with radar rain rate measurements across five case studies showed substantial improvement in the combined algorithm approach when compared to the use of any single microwave algorithm. An automated neural network cloud classifier for use over both land and ocean was independently developed and tested on Advanced Very High Resolution Radiometer (AVHRR) data. The global classifier achieved strict accuracy for 82% of the test samples, while a more localized version achieved strict accuracy for 89% of its own test set. These numbers provide hope for the eventual development of a global automated cloud classifier for use throughout the tropics and the temperate zones. The localized classifier was used in conjunction with gridded 15-minute averaged radar rain rates at 8km resolution produced from the current operational network of National Weather Service (NWS) radars, to investigate the relation between cloud type and rain rate over three regions of the continental United States and adjacent waters. The results indicate a substantially lower amount of available moisture in the Front Range of the Rocky Mountains than in the Midwest or in the eastern Gulf of Mexico.

7746 CONCENTRATIONS OF FORMALDEHYDE IN RAIN WATERS ...

African Journals Online (AJOL)

Win7Ent

2013-06-03

Jun 3, 2013 ... The chromotropic acid method described by the. National Institute for ... concentration range of the formaldehyde in the rain waters varied from month to month throughout the six ... vicinity of vegetation [3]. Formaldehyde is the ...

Characterization of polycyclic aromatic hydrocarbons in fog-rain events.

Science.gov (United States)

Li, Xiang; Li, Pengfei; Yan, Lili; Chen, Jianmin; Cheng, Tiantao; Xu, Shifen

2011-11-01

Atmospheric polycyclic aromatic hydrocarbons (PAHs) mainly originate from incomplete combustion or pyrolysis of materials containing carbon and hydrogen. They exist in gas and particle phases, as well as dissolved or suspended in precipitation (fog or rain). Current studies in atmospheric PAHs are predominantly focused on fog and rainwater samples. Some sampling difficulties are associated with fog samples. This study presented the first observation of the characteristics of PAHs in fog samples using a solid phase microextraction (SPME) technique. Eighteen fog samples were collected during ten fog events from March to December 2009 in the Shanghai area. PAHs were extracted by SPME and analyzed by gas chromatography-mass spectrometry (GC-MS). As the compounds were partially soluble in water, with solubility decreasing with increasing molecular weight, low molecular weight (LMW) PAH compounds were universally found in the fog water samples. Naphthalene (NaP), phenanthrene (Phe), anthracene (Ant) and fluoranthene (Flo) were dominant compounds in fog water. The total PAH concentration in fog water ranged from 0.03 to 6.67 μg L(-1) (mean of 1.06 μg L(-1)), and was much higher in winter than in summer. The concentration of PAHs in fog or rain water decreased after undergoing a pre-rain or pre-fog wash. The average concentration of PAHs was higher in fog than in rain. Diagnostic ratio analysis suggested that petroleum and combustion were the dominant contributors to PAHs in urban Shanghai. Backward trajectories were calculated to determine the origin of the air masses, showing that air masses were mostly from the northeast territory.

Warm Debris Disks from WISE

Science.gov (United States)

Padgett, Deborah L.

2011-01-01

"The Wide Field Infrared Survey Explorer (WISE) has just completed a sensitive all-sky survey in photometric bands at 3.4, 4.6, 12, and 22 microns. We report on a preliminary investigation of main sequence Hipparcos and Tycho catalog stars with 22 micron emission in excess of photospheric levels. This warm excess emission traces material in the circumstellar region likely to host terrestrial planets and is preferentially found in young systems with ages warm debris disk candidates are detected among FGK stars and a similar number of A stars within 120 pc. We are in the process of obtaining spectra to determine spectral types and activity level of these stars and are using HST, Herschel and Keck to characterize the dust, multiplicity, and substellar companions of these systems. In this contribution, we will discuss source selection methods and individual examples from among the WISE debris disk candidates. "

Warming of the Indian Ocean Threatens Eastern and Southern Africa, but could be Mitigated by Agricultural Development

Science.gov (United States)

Funk, Chris; Dettinger, Michael D.; Brown, Molly E.; Michaelsen, Joel C.; Verdin, James P.; Barlow, Mathew; Howell, Andrew

2008-01-01

Since 1980, the number of undernourished people in eastern and southern Africa has more than doubled. Rural development stalled and rural poverty expanded during the 1990s. Population growth remains very high and declining per capita agricultural capacity retards progress towards Millennium Development goals. Analyses of in situ station data and satellite observations of precipitation identify another problematic trend. Main growing season rainfall receipts have diminished by approximately 15% in food insecure countries clustered along the western rim of the Indian Ocean. Occurring during the main growing seasons in poor countries dependent on rain fed agriculture, these declines are societally dangerous. Will they persist or intensify? Tracing moisture deficits upstream to an anthropogenically warming Indian Ocean leads us to conclude that further rainfall declines are likely. We present analyses suggesting that warming in the central Indian Ocean disrupts onshore moisture transports, reducing continental rainfall. Thus late 20th century anthropogenic Indian Ocean warming has probably already produced societally dangerous climate change by creating drought and social disruption in some of the world's most fragile food economies. We quantify the potential impacts of the observed precipitation and agricultural capacity trends by modeling millions of undernourished people as a function of rainfall, population, cultivated area, seed and fertilizer use. Persistence of current tendencies may result in a 50% increase in undernourished people. On the other hand, modest increases in per capita agricultural productivity could more than offset the observed precipitation declines. Investing in agricultural development can help mitigate climate change while decreasing rural poverty and vulnerability.

High resolution radar-rain gauge data merging for urban hydrology: current practice and beyond

Science.gov (United States)

Ochoa Rodriguez, Susana; Wang, Li-Pen; Bailey, Andy; Willems, Patrick; Onof, Christian

2017-04-01

In this work a thorough test is conducted of radar-rain gauge merging techniques at urban scales, under different climatological conditions and rain gauge density scenarios. The aim is to provide guidance regarding the suitability and application of merging methods at urban scales, which is lacking at present. The test is conducted based upon two pilot locations, i.e. the cities of Edinburgh (254 km^2) and Birmingham (431 km^2), for which a total of 96 and 84 tipping bucket rain gauges were respectively available, alongside radar QPEs, dense runoff records and urban drainage models. Three merging techniques, namely Mean Field Bias (MFB) adjustment, kriging with external (KED) and Bayesian (BAY) combination, were selected for testing on grounds of performance and common use. They were initially tested as they were originally formulated and as they are reportedly commonly applied using typically available radar and rain gauge data. Afterwards, they were tested in combination with two special treatments which were identified as having the potential to improve merging applicability for urban hydrology: (1) reduction of temporal sampling errors in radar QPEs through temporal interpolation and (2) singularity-based decomposition of radar QPEs prior to merging. These treatments ultimately aim at improving the consistency between radar and rain gauge records, which has been identified as the chief factor affecting merging performance and is particularly challenging at the fine spatial-temporal resolutions required for urban applications. The main findings of this study are the following: - All merging methods were found to improve the applicability of radar QPEs for urban hydrological applications, but the degree of improvement they provide and the added value of radar information vary for each merging method and are also a function of climatological conditions and rain gauge density scenarios. - Overall, KED displayed the best performance, with BAY being a close second

Peranan Environmental Accounting Terhadap Global Warming

OpenAIRE

Martusa, Riki

2009-01-01

This article explores about is global warming. The distortion of nature causes global warming. Industrial sector is one of global warming incurred. Some nations create a group to cope this matter. They try to reduce carbon emission as one of global warming causes by controlling industrial carbon emission through financial reporting. This article explores normatively roles of environmental accounting in cope with global warming.  

Rain and contamination tests on HVDC wall bushings with and without RTV coatings

International Nuclear Information System (INIS)

Schneider, H.M.; Hall, J.F.; Nellis, C.L.; Low, S.S.; Lorden, D.J.

1991-01-01

In this paper results of tests made to determine the ability of room temperature vulcanized (RTV) silicone rubber coatings to improve the performance of HVDC wall bushings are described. The behavior of uncoated full scale ± 500 kV wall bushings is first determined in wetting conditions consisting of nonuniform rain and fog with various amounts of pre-deposited surface contamination. Parameters affecting flashover performance, such as polarity, rain conductivity, and contamination severity are discussed. Results of nonuniform rain tests on an RTV coated wall bushing are reported

Flying in the rain: hovering performance of Anna's hummingbirds under varied precipitation.

Science.gov (United States)

Ortega-Jimenez, Victor Manuel; Dudley, Robert

2012-10-07

Flight in rain represents a greater challenge for smaller animals because the relative effects of water loading and drop impact are greater at reduced scales given the increased ratios of surface area to mass. Nevertheless, it is well known that small volant taxa such as hummingbirds can continue foraging even in extreme precipitation. Here, we evaluated the effect of four rain intensities (i.e. zero, light, moderate and heavy) on the hovering performance of Anna's hummingbirds (Calypte anna) under laboratory conditions. Light-to-moderate rain had only a marginal effect on flight kinematics; wingbeat frequency of individuals in moderate rain was reduced by 7 per cent relative to control conditions. By contrast, birds hovering in heavy rain adopted more horizontal body and tail positions, and also increased wingbeat frequency substantially, while reducing stroke amplitude when compared with control conditions. The ratio between peak forces produced by single drops on a wing and on a solid surface suggests that feathers can absorb associated impact forces by up to approximately 50 per cent. Remarkably, hummingbirds hovered well even under heavy precipitation (i.e. 270 mm h(-1)) with no apparent loss of control, although mechanical power output assuming perfect and zero storage of elastic energy was estimated to be about 9 and 57 per cent higher, respectively, compared with normal hovering.

[Effects of simulated acid rain on decomposition of soil organic carbon and crop straw].

Science.gov (United States)

Zhu, Xue-Zhu; Huang, Yao; Yang, Xin-Zhong

2009-02-01

To evaluate the effects of acid rain on the organic carbon decomposition in different acidity soils, a 40-day incubation test was conducted with the paddy soils of pH 5.48, 6.70 and 8.18. The soils were amended with 0 and 15 g x kg(-1) of rice straw, adjusted to the moisture content of 400 g x kg(-1) air-dried soil by using simulated rain of pH 6.0, 4.5, and 3.0, and incubated at 20 degrees C. The results showed that straw, acid rain, and soil co-affected the CO2 emission from soil system. The amendment of straw increased the soil CO2 emission rate significantly. Acid rain had no significant effects on soil organic carbon decomposition, but significantly affected the straw decomposition in soil. When treated with pH 3.0 acid rain, the amount of decomposed straw over 40-day incubation in acid (pH 5.48) and alkaline (pH 8.18) soils was 8% higher, while that in neutral soil (pH 6.70) was 15% lower, compared to the treatment of pH 6.0 rain. In the treatment of pH 3.0 acid rain, the decomposition rate of soil organic C in acid (pH 5.48) soil was 43% and 50% (P pH 6.70) and alkaline (pH 8.18) soils, while the decomposition rate of straw in neutral soil was 17% and 16% (P < 0.05) lower than that in acid and alkaline soils, respectively.

Ecosystem responses to warming and watering in typical and desert steppes

Science.gov (United States)

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.

Combined effects of simulated acid rain and lanthanum chloride on chloroplast structure and functional elements in rice.

Science.gov (United States)

Hu, Huiqing; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

2016-05-01

Acid rain and rare earth element (REE) pollution exist simultaneously in many agricultural regions. However, how REE pollution and acid rain affect plant growth in combination remains largely unknown. In this study, the combined effects of simulated acid rain and lanthanum chloride (LaCl3) on chloroplast morphology, chloroplast ultrastructure, functional element contents, chlorophyll content, and the net photosynthetic rate (P n) in rice (Oryza sativa) were investigated by simulating acid rain and rare earth pollution. Under the combined treatment of simulated acid rain at pH 4.5 and 0.08 mM LaCl3, the chloroplast membrane was smooth, proteins on this membrane were uniform, chloroplast structure was integrated, and the thylakoids were orderly arranged, and simulated acid rain and LaCl3 exhibited a mild antagonistic effect; the Mg, Ca, Mn contents, the chlorophyll content, and the P n increased under this combined treatment, with a synergistic effect of simulated acid rain and LaCl3. Under other combined treatments of simulated acid rain and LaCl3, the chloroplast membrane surface was uneven, a clear "hole" was observed on the surface of chloroplasts, and the thylakoids were dissolved and loose; and the P n and contents of functional elements (P, Mg, K, Ca, Mn, Fe, Ni, Cu, Zn and Mo) and chlorophyll decreased. Under these combined treatments, simulated acid rain and LaCl3 exhibited a synergistic effect. Based on the above results, a model of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis was established in order to reveal the combined effects on plant photosynthesis, especially on the photosynthetic organelle-chloroplast. Our results would provide some references for further understanding the mechanism of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis.

Characteristics and transport of organochlorine pesticides in urban environment: air, dust, rain, canopy throughfall, and runoff.

Science.gov (United States)

Zhang, Wei; Ye, Youbin; Hu, Dan; Ou, Langbo; Wang, Xuejun

2010-11-01

Characteristics and transport of organochlorine pesticides (OCPs) in urban multiple environments, including air, dust, rain, canopy throughfall, and runoff water, are explored in this study. Hexachlorocyclohexanes (HCHs) dominated in both air and rain water, and dichlorodiphenyltrichloroethane (DDT) related substances showed a higher affinity to dust. Relatively high concentrations of DDT and dichlorodiphenyldichloroethylene (DDE) in air, rain and dust imply that technical DDT in the environment has been degrading, and there may be unknown local or regional emission sources that contain DDTs in the study area. Source identification showed that DDTs in Beijing urban environments with a fresh signature may originate from the atmospheric transport from remote areas. The ratio of α-/γ-HCH in dust, rain, canopy throughfall and runoff were close to 1, indicating the possible use of lindane. OCPs in runoff were transported from various sources including rain, dust, and canopy throughfall. In runoff, DDTs and hexachlorobenzene (HCB) were mainly transported from dust, and HCHs were mainly from rain and canopy throughfall.

Rain-induced changes in soil CO2 flux and microbial community composition in a tropical forest of China.

Science.gov (United States)

Deng, Qi; Hui, Dafeng; Chu, Guowei; Han, Xi; Zhang, Quanfa

2017-07-17

Rain-induced soil CO 2 pulse, a rapid excitation in soil CO 2 flux after rain, is ubiquitously observed in terrestrial ecosystems, yet the underlying mechanisms in tropical forests are still not clear. We conducted a rain simulation experiment to quantify rain-induced changes in soil CO 2 flux and microbial community composition in a tropical forest. Soil CO 2 flux rapidly increased by ~83% after rains, accompanied by increases in both bacterial (~51%) and fungal (~58%) Phospholipid Fatty Acids (PLFA) biomass. However, soil CO 2 flux and microbial community in the plots without litters showed limited response to rains. Direct releases of CO 2 from litter layer only accounted for ~19% increases in soil CO 2 flux, suggesting that the leaching of dissolved organic carbon (DOC) from litter layer to the topsoil is the major cause of rain-induced soil CO 2 pulse. In addition, rain-induced changes in soil CO 2 flux and microbial PLFA biomass decreased with increasing rain sizes, but they were positively correlated with litter-leached DOC concentration rather than total DOC flux. Our findings reveal an important role of litter-leached DOC input in regulating rain-induced soil CO 2 pulses and microbial community composition, and may have significant implications for CO 2 losses from tropical forest soils under future rainfall changes.

Sudden Stratospheric Warming Compendium

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Sudden Stratospheric Warming Compendium (SSWC) data set documents the stratospheric, tropospheric, and surface climate impacts of sudden stratospheric warmings. This...

Simulated Acid Rain-induced Alterations in Flowering, Leaf ...

African Journals Online (AJOL)

Evaluation of SAR effects on budding, flowering, leaf abscission and pollen development revealed that ... Keywords: Simulated acid rain, Helianthus annuus, flowering, leaf abscission, pollen germination, sunflower. ... HOW TO USE AJOL.

Monitoring Global Precipitation through UCI CHRS's RainMapper App on Mobile Devices

Science.gov (United States)

Nguyen, P.; Huynh, P.; Braithwaite, D.; Hsu, K. L.; Sorooshian, S.

2014-12-01

The Water and Development Information for Arid Lands-a Global Network (G-WADI) Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks—Cloud Classification System (PERSIANN-CCS) GeoServer has been developed through a collaboration between the Center for Hydrometeorology and Remote Sensing (CHRS) at the University of California, Irvine (UCI) and the UNESCO's International Hydrological Program (IHP). G-WADI PERSIANN-CCS GeoServer provides near real-time high resolution (0.04o, approx 4km) global (60oN - 60oS) satellite precipitation estimated by the PERSIANN-CCS algorithm developed by the scientists at CHRS. The G-WADI PERSIANN-CCS GeoServer utilizes the open-source MapServer software from the University of Minnesota to provide a user-friendly web-based mapping and visualization of satellite precipitation data. Recent efforts have been made by the scientists at CHRS to provide free on-the-go access to the PERSIANN-CCS precipitation data through an application named RainMapper for mobile devices. RainMapper provides visualization of global satellite precipitation of the most recent 3, 6, 12, 24, 48 and 72-hour periods overlaid with various basemaps. RainMapper uses the Google maps application programing interface (API) and embedded global positioning system (GPS) access to better monitor the global precipitation data on mobile devices. Functionalities include using geographical searching with voice recognition technologies make it easy for the user to explore near real-time precipitation in a certain location. RainMapper also allows for conveniently sharing the precipitation information and visualizations with the public through social networks such as Facebook and Twitter. RainMapper is available for iOS and Android devices and can be downloaded (free) from the App Store and Google Play. The usefulness of RainMapper was demonstrated through an application in tracking the evolution of the recent Rammasun Typhoon over the

Arbuscular-mycorrhizal networks inhibit Eucalyptus tetrodonta seedlings in rain forest soil microcosms.

Directory of Open Access Journals (Sweden)

David P Janos

Full Text Available Eucalyptus tetrodonta, a co-dominant tree species of tropical, northern Australian savannas, does not invade adjacent monsoon rain forest unless the forest is burnt intensely. Such facilitation by fire of seedling establishment is known as the "ashbed effect." Because the ashbed effect might involve disruption of common mycorrhizal networks, we hypothesized that in the absence of fire, intact rain forest arbuscular mycorrhizal (AM networks inhibit E. tetrodonta seedlings. Although arbuscular mycorrhizas predominate in the rain forest, common tree species of the northern Australian savannas (including adult E. tetrodonta host ectomycorrhizas. To test our hypothesis, we grew E. tetrodonta and Ceiba pentandra (an AM-responsive species used to confirm treatments separately in microcosms of ambient or methyl-bromide fumigated rain forest soil with or without severing potential mycorrhizal fungus connections to an AM nurse plant, Litsea glutinosa. As expected, C. pentandra formed mycorrhizas in all treatments but had the most root colonization and grew fastest in ambient soil. E. tetrodonta seedlings also formed AM in all treatments, but severing hyphae in fumigated soil produced the least colonization and the best growth. Three of ten E. tetrodonta seedlings in ambient soil with intact network hyphae died. Because foliar chlorosis was symptomatic of iron deficiency, after 130 days we began to fertilize half the E. tetrodonta seedlings in ambient soil with an iron solution. Iron fertilization completely remedied chlorosis and stimulated leaf growth. Our microcosm results suggest that in intact rain forest, common AM networks mediate belowground competition and AM fungi may exacerbate iron deficiency, thereby enhancing resistance to E. tetrodonta invasion. Common AM networks-previously unrecognized as contributors to the ashbed effect-probably help to maintain the rain forest-savanna boundary.

Explosive Radiation of Malpighiales Supports a Mid-Cretaceous Origin of Modern Tropical Rain Forests

OpenAIRE

Wurdack, Kenneth J.; Jaramillo, Carlos A.; Davis, Charles; Webb, Campbell O.; Donoghue, Michael J.

2005-01-01

Fossil data have been interpreted as indicating that Late Cretaceous tropical forests were open and dry adapted and that modern closed-canopy rain forest did not originate until after the Cretaceous-Tertiary (K/T) boundary. However, some mid-Cretaceous leaf floras have been interpreted as rain forest. Molecular divergence-time estimates within the clade Malpighiales, which constitute a large percentage of species in the shaded, shrub, and small tree layer in tropical rain forests worldwide, p...

TOPICAL REVIEW Warm spraying—a novel coating process based on high-velocity impact of solid particles

Directory of Open Access Journals (Sweden)

Seiji Kuroda et al

2008-01-01

Full Text Available In recent years, coating processes based on the impact of high-velocity solid particles such as cold spraying and aerosol deposition have been developed and attracting much industrial attention. A novel coating process called 'warm spraying' has been developed, in which coatings are formed by the high-velocity impact of solid powder particles heated to appropriate temperatures below the melting point of the powder material. The advantages of such process are as follows: (1 the critical velocity needed to form a coating can be significantly lowered by heating, (2 the degradation of feedstock powder such as oxidation can be significantly controlled compared with conventional thermal spraying where powder is molten, and (3 various coating structures can be realized from porous to dense ones by controlling the temperature and velocity of the particles. The principles and characteristics of this new process are discussed in light of other existing spray processes such as high-velocity oxy-fuel spraying and cold spraying. The gas dynamics of particle heating and acceleration by the spraying apparatus as well as the high-velocity impact phenomena of powder particles are discussed in detail. Several examples of depositing heat sensitive materials such as titanium, metallic glass, WC–Co cermet and polymers are described with potential industrial applications.

Regeneration in natural and logged tropical rain forest : modelling seed dispersal and regeneration

NARCIS (Netherlands)

Ulft, Lambertus Henricus van

2004-01-01

Regeneration and disturbance are thought to play key roles in the maintenance of the high tree species diversity in tropical rain forests. Nevertheless, the earliest stages in the regeneration of tropical rain forest trees, from seed production to established seedlings, have received little

Performance Investigation of FSO-OFDM Communication Systems under the Heavy Rain Weather

Science.gov (United States)

Rashidi, Florence; He, Jing; Chen, Lin

2017-12-01

The challenge in the free-space optical (FSO) communication is the propagation of optical signal through different atmospheric conditions such as rain, snow and fog. In this paper, an orthogonal frequency-division multiplexing technique (OFDM) is proposed in the FSO communication system. Meanwhile, considering the rain attenuation models based on Marshal & Palmer and Carbonneau models, the performance of FSO communication system based on the OFDM is evaluated under the heavy-rain condition in Changsha, China. The simulation results show that, under a heavy-rainfall condition of 106.18 mm/h, with an attenuation factor of 7 dB/km based on the Marshal & Palmer model, the bit rate of 2.5 and 4.0 Gbps data can be transmitted over the FSO channels of 1.6 and 1.3 km, respectively, and the bit error rate of less than 1E - 4 can be achieved. In addition, the effect on rain attenuation over the FSO communication system based on the Marshal & Palmer model is less than that of the Carbonneau model.

Military Implications of Global Warming.

Science.gov (United States)

1999-05-20

U.S. environmental issues also have important global implications. This paper analyzes current U.S. Policy as it pertains to global warming and climate...for military involvement to reduce global warming . Global warming and other environmental issues are important to the U.S. military. As the United

Dissolved nutrients and atrazine removal by column-scale monophasic and biphasic rain garden model systems.

Science.gov (United States)

Yang, Hanbae; McCoy, Edward L; Grewal, Parwinder S; Dick, Warren A

2010-08-01

Rain gardens are bioretention systems that have the potential to reduce peak runoff flow and improve water quality in a natural and aesthetically pleasing manner. We compared hydraulic performance and removal efficiencies of nutrients and atrazine in a monophasic rain garden design versus a biphasic design at a column-scale using simulated runoff. The biphasic rain garden was designed to increase retention time and removal efficiency of runoff pollutants by creating a sequence of water saturated to unsaturated conditions. We also evaluated the effect of C substrate availability on pollutant removal efficiency in the biphasic rain garden. Five simulated runoff events with various concentrations of runoff pollutants (i.e. nitrate, phosphate, and atrazine) were applied to the monophasic and biphasic rain gardens once every 5d. Hydraulic performance was consistent over the five simulated runoff events. Peak flow was reduced by approximately 56% for the monophasic design and 80% for the biphasic design. Both rain garden systems showed excellent removal efficiency of phosphate (89-100%) and atrazine (84-100%). However, significantly (prain garden (29-39%). Addition of C substrate in the form of glucose increased removal efficiency of nitrate significantly (prain gardens. (c) 2010 Elsevier Ltd. All rights reserved.

Can biomass responses to warming at plant to ecosystem levels be predicted by leaf-level responses?

Science.gov (United States)

Xia, J.; Shao, J.; Zhou, X.; Yan, W.; Lu, M.

2015-12-01

Global warming has the profound impacts on terrestrial C processes from leaf to ecosystem scales, potentially feeding back to climate dynamics. Although numerous studies had investigated the effects of warming on C processes from leaf to plant and ecosystem levels, how leaf-level responses to warming scale up to biomass responses at plant, population, and community levels are largely unknown. In this study, we compiled a dataset from 468 papers at 300 experimental sites and synthesized the warming effects on leaf-level parameters, and plant, population and ecosystem biomass. Our results showed that responses of plant biomass to warming mainly resulted from the changed leaf area rather than the altered photosynthetic capacity. The response of ecosystem biomass to warming was weaker than those of leaf area and plant biomass. However, the scaling functions from responses of leaf area to plant biomass to warming were different in diverse forest types, but functions were similar in non-forested biomes. In addition, it is challenging to scale the biomass responses from plant up to ecosystem. These results indicated that leaf area might be the appropriate index for plant biomass response to warming, and the interspecific competition might hamper the scaling of the warming effects on plant and ecosystem levels, suggesting that the acclimation capacity of plant community should be incorporated into land surface models to improve the prediction of climate-C cycle feedback.

Changes in ENSO amplitude under climate warming and cooling

Science.gov (United States)

Wang, Yingying; Luo, Yiyong; Lu, Jian; Liu, Fukai

2018-05-01

The response of ENSO amplitude to climate warming and cooling is investigated using the Community Earth System Model (CESM), in which the warming and cooling scenarios are designed by adding heat fluxes of equal amplitude but opposite sign onto the ocean surface, respectively. Results show that the warming induces an increase of the ENSO amplitude but the cooling gives rise to a decrease of the ENSO amplitude, and these changes are robust in statistics. A mixed layer heat budget analysis finds that the increasing (decreasing) SST tendency under climate warming (cooling) is mainly due to an enhancement (weakening) of dynamical feedback processes over the equatorial Pacific, including zonal advective (ZA) feedback, meridional advective (MA) feedback, thermocline (TH) feedback, and Ekman (EK) feedback. As the climate warms, a wind anomaly of the same magnitude across the equatorial Pacific can induce a stronger zonal current change in the east (i.e., a stronger ZA feedback), which in turn produces a greater weakening of upwelling (i.e., a stronger EK feedback) and thus a larger thermocline change (i.e., a stronger TH feedback). In response to the climate warming, in addition, the MA feedback is also strengthened due to an enhancement of the meridional SST gradient around the equator resulting from a weakening of the subtropical cells (STCs). It should be noted that the weakened STCs itself has a negative contribution to the change of the MA feedback which, however, appears to be secondary. And vice versa for the cooling case. Bjerknes linear stability (BJ) index is also evaluated for the linear stability of ENSO, with remarkably larger (smaller) BJ index found for the warming (cooling) case.

Use of emulsion for warm mix asphalt

Directory of Open Access Journals (Sweden)

Mahabir Panda

2017-06-01

Full Text Available Due to increase in energy costs and emission problems in hot mix asphalt usually used, it brought a great interest to the researchers to develop the warm mix technology for pavement constructions. Commonly known as warm mix asphalt (WMA, it is a typical method in the bituminous paving technology, which allows production and placement of bituminous mixes at lower temperatures than that used for hot mix asphalt (HMA. The WMA involves an environmental friendly production process that utilises organic additives, chemical additives and water based technologies. The organic and chemical additives are normally very costly and still involve certain amount of environmental issues. These factors motivated the authors to take up this technology using simple, environment friendly and somewhat cost effective procedure. In this study, an attempt has been made to prepare warm mixes by first pre-coating the aggregates with medium setting bitumen emulsion (MS and then mixing the semi-coated aggregates with VG 30 bitumen at a lower temperature than normally required. After a number of trials it was observed that mostly three mixing temperatures, namely temperatures 110 °C, 120 °C and 130 °C were appropriate to form the bituminous mixes with satisfactory homogeneity and consistency and as such were maintained throughout this study. Marshall samples for paving mixes were prepared using this procedure for dense bituminous macadam (DBM gradings as per the specifications of Ministry of Road Transport and Highways (MORTH and subsequently Marshall properties of the resultant mixes were studied with the main objective of deciding the different parameters that were considered for development of appropriate warm mix asphalt. In this study it has been observed that out of three mixing temperatures tried, the mixes prepared at 120 °C with bitumen-emulsion composition of 80B:20E for DBM warm mix, offer highest Marshall stability and highest indirect tensile strength

A simple rain attenuation model for earth-space radio links operating at 10-35 GHz

Science.gov (United States)

Stutzman, W. L.; Yon, K. M.

1986-01-01

The simple attenuation model has been improved from an earlier version and now includes the effect of wave polarization. The model is for the prediction of rain attenuation statistics on earth-space communication links operating in the 10-35 GHz band. Simple calculations produce attenuation values as a function of average rain rate. These together with rain rate statistics (either measured or predicted) can be used to predict annual rain attenuation statistics. In this paper model predictions are compared to measured data from a data base of 62 experiments performed in the U.S., Europe, and Japan. Comparisons are also made to predictions from other models.

Computer Simulation of Material Flow in Warm-forming Bimetallic Components

Science.gov (United States)

Kong, T. F.; Chan, L. C.; Lee, T. C.

2007-05-01

Bimetallic components take advantage of two different metals or alloys so that their applicable performance, weight and cost can be optimized. However, since each material has its own flow properties and mechanical behaviour, heterogeneous material flows will occur during the bimetal forming process. Those controls of process parameters are relatively more complicated than forming single metals. Most previous studies in bimetal forming have focused mainly on cold forming, and less relevant information about the warm forming has been provided. Indeed, changes of temperature and heat transfer between two materials are the significant factors which can highly influence the success of the process. Therefore, this paper presents a study of the material flow in warm-forming bimetallic components using finite-element (FE) simulation in order to determine the suitable process parameters for attaining the complete die filling. A watch-case-like component made of stainless steel (AISI-316L) and aluminium alloy (AL-6063) was used as the example. The warm-forming processes were simulated with the punch speeds V of 40, 80, and 120 mm/s and the initial temperatures of the stainless steel TiSS of 625, 675, 725, 775, 825, 875, 925, 975, and 1025 °C. The results showed that the AL-6063 flowed faster than the AISI-316L and so the incomplete die filling was only found in the AISI-316L region. A higher TiSS was recommended to avoid incomplete die filling. The reduction of V is also suggested because this can save the forming energy and prevent the damage of tooling. Eventually, with the experimental verification, the results from the simulation were in agreement with those of the experiments. On the basis of the results of this study, engineers can gain a better understanding of the material flow in warm-forming bimetallic components, and be able to determine more efficiently the punch speed and initial material temperature for the process.

Future changes in the East Asian rain band projected by global atmospheric models with 20-km and 60-km grid size

Energy Technology Data Exchange (ETDEWEB)

Kusunoki, Shoji; Mizuta, Ryo [Meteorological Research Institute, Climate Research Department, Tsukuba, Ibaraki (Japan); Matsueda, Mio [Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Tsukuba, Ibaraki (Japan)

2011-12-15

Global warming projection experiments were conducted using a 20-km mesh global atmospheric model, focusing on the change in the rain band of East Asian summer monsoon. To assess the uncertainty of climate change projections, we performed ensemble simulations with the 60-km resolution model combining four different SSTs and three atmospheric initial conditions. In the present-day climate simulations, the 20-km model reproduces the rain band of East Asian summer monsoon better than lower resolution models in terms of geographical distribution and seasonal march. In the future climate simulation by the 20-km model, precipitation increases over the Yangtze River valley in May through July, Korean peninsula in May, and Japan in July. The termination of rainy season over Japan tends to be delayed until August. Ensemble simulations by the 60-km model show that precipitation in the future climate for July increases over the Yangtze River valley, the East China Sea and Japan. These changes in precipitation are partly consistent with those projected by the 20-km model. Simulations by the 20-km and 60-km models consistently show that in the future climate the termination of rainy season over Japan tends to be delayed until August. The changes in the vertically integrated water vapor flux show the intensification of clockwise moisture transport over the western Pacific subtropical high. Most precipitation changes over the East Asia can be interpreted as the moisture convergence resulting from change in the horizontal transport of water vapor. (orig.)

Apocalypse soon? Dire messages reduce belief in global warming by contradicting just-world beliefs.

Science.gov (United States)

Feinberg, Matthew; Willer, Robb

2011-01-01

Though scientific evidence for the existence of global warming continues to mount, in the United States and other countries belief in global warming has stagnated or even decreased in recent years. One possible explanation for this pattern is that information about the potentially dire consequences of global warming threatens deeply held beliefs that the world is just, orderly, and stable. Individuals overcome this threat by denying or discounting the existence of global warming, and this process ultimately results in decreased willingness to counteract climate change. Two experiments provide support for this explanation of the dynamics of belief in global warming, suggesting that less dire messaging could be more effective for promoting public understanding of climate-change research.

Alterations in cytosol free calcium in horseradish roots simultaneously exposed to lanthanum(III) and acid rain.

Science.gov (United States)

Zhang, Xuanbo; Wang, Lihong; Zhou, Anhua; Zhou, Qing; Huang, Xiaohua

2016-04-01

The extensive use of rare earth elements (REEs) has increased their environmental levels. REE pollution concomitant with acid rain in many agricultural regions can affect crop growth. Cytosol free calcium ions (Ca(2+)) play an important role in almost all cellular activities. However, no data have been reported regarding the role of cytosol free Ca(2+) in plant roots simultaneously exposed to REE and acid rain. In this study, the effects of exposures to lanthanum(III) and acid rain, independently and in combination, on cytosol free Ca(2+) levels, root activity, metal contents, biomass, cytosol pH and La contents in horseradish roots were investigated. The simultaneous exposures to La(III) and acid rain increased or decreased the cytosol free Ca(2+) levels, depending on the concentration of La(III), and these effects were more evident than independent exposure to La(III) or acid rain. In combined exposures, cytosol free Ca(2+) played an important role in the regulation of root activity, metal contents and biomass. These roles were closely related to La(III) dose, acid rain strength and treatment mode (independent exposure or simultaneous exposure). A low concentration of La(III) (20 mg L(-1)) could alleviate the adverse effects on the roots caused by acid rain, and the combined exposures at higher concentrations of La(III) and acid rain had synergic effects on the roots. Copyright © 2015 Elsevier Inc. All rights reserved.

Greenhouse warming and changes in sea level

NARCIS (Netherlands)

Oerlemans, J.

1989-01-01

It is likely that the anticipated warming due to the effect of increasing concentration of carbon dioxide and other greenhouse gases will lead to a further and faster rise in world mean sea level. There are many processes in the climate system controlling sea level, but the most important

Changes in Intense Precipitation Events in West Africa and the central U.S. under Global Warming

Energy Technology Data Exchange (ETDEWEB)

Cook, Kerry H. [Univ. of Texas, Austin, TX (United States); Vizy, Edward [Univ. of Texas, Austin, TX (United States)

2016-02-08

The purpose of the proposed project is to improve our understanding of the physical processes and large-scale connectivity of changes in intense precipitation events (high rainfall rates) under global warming in West Africa and the central U.S., including relationships with low-frequency modes of variability. This is in response to the requested subject area #2 “simulation of climate extremes under a changing climate … to better quantify the frequency, duration, and intensity of extreme events under climate change and elucidate the role of low frequency climate variability in modulating extremes.” We will use a regional climate model and emphasize an understanding of the physical processes that lead to an intensification of rainfall. The project objectives are as follows: 1. Understand the processes responsible for simulated changes in warm-season rainfall intensity and frequency over West Africa and the Central U.S. associated with greenhouse gas-induced global warming 2. Understand the relationship between changes in warm-season rainfall intensity and frequency, which generally occur on regional space scales, and the larger-scale global warming signal by considering modifications of low-frequency modes of variability. 3. Relate changes simulated on regional space scales to global-scale theories of how and why atmospheric moisture levels and rainfall should change as climate warms.

Constraining the trigger for an ancient warming episode

Science.gov (United States)

Schultz, Colin

2011-08-01

The Paleocene epoch (˜66-56 million years ago) was sandwiched between sudden climate shifts and mass extinctions. The boundary between the end of the Paleocene and the beginning of the Eocene (the P-E boundary) saw the global average temperature soar by 5°C over a few thousand years, leading to a pronounced reorganization of both terrestrial and oceanic plant and animal communities. The P-E boundary warming was triggered by an influx of atmospheric carbon dioxide, but the influx's ultimate trigger is still being debated. Other prominent warming events within the Paleogene (˜66-23 million years ago), the broad time span that encompasses the Paleocene and Eocene, have been linked to regularly recurring changes in the eccentricity of the Earth's orbit that take place on 100,000- and 405,000-year cycles. Proponents of this view suggest that an alignment of the two cycles could lead to the warming of deep ocean waters, melting frozen methane and triggering an increase in atmospheric carbon dioxide. However, some studies have suggested that the P-E boundary warming was instead the product of geological processes, where carbon-rich rocks were baked by injected magma, which eventually liberated the carbon to the atmosphere. Deciding between proposed explanations for the cause of the P-E warming, whether they are astronomical or geological, depends on accurately pinning the event in time. (Geochemistry, Geophysics, Geosystems, doi:10.1029/2010GC003426, 2011)

Characterization of heavy metal desorption from road-deposited sediment under acid rain scenarios.

Science.gov (United States)

Zhao, Bo; Liu, An; Wu, Guangxue; Li, Dunzhu; Guan, Yuntao

2017-01-01

Road-deposited sediments (RDS) on urban impervious surfaces are important carriers of heavy metals. Dissolved heavy metals that come from RDS influenced by acid rain, are more harmful to urban receiving water than particulate parts. RDS and its associated heavy metals were investigated at typical functional areas, including industrial, commercial and residential sites, in Guangdong, Southern China, which was an acid rain sensitive area. Total and dissolved heavy metals in five particle size fractions were analyzed using a shaking method under acid rain scenarios. Investigated heavy metals showed no difference in the proportion of dissolved fraction in the solution under different acid rain pHs above 3.0, regardless of land use. Dissolved loading of heavy metals related to organic carbon content were different in runoff from main traffic roads of three land use types. Coarse particles (>150μm) that could be efficiently removed by conventional street sweepers, accounted for 55.1%-47.1% of the total dissolved metal loading in runoff with pH3.0-5.6. The obtained findings provided a significant scientific basis to understand heavy metal release and influence of RDS grain-size distribution and land use in dissolved heavy metal pollution affected by acid rain. Copyright © 2016. Published by Elsevier B.V.

Chemical characterization of fog and rain water collected at the eastern Andes cordillera

Science.gov (United States)

Beiderwieden, E.; Wrzesinsky, T.; Klemm, O.

2005-09-01

During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the "El Tiro" site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl-, NO3-, PO43-, and SO42- were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 μS cm-1 for the fog and 6 μS cm-1 for the rain. The continent samples exhibit higher concentrations of most ions as compared to the pacific samples, but these differences could not be detected statistically.

Combining meteorological radar and network of rain gauges data for space–time model development

OpenAIRE

Pastoriza, Vicente; Núñez Fernández, Adolfo; Machado, Fernando; Mariño, Perfecto; Pérez Fontán, Fernando; Fiebig, Uwe-Carsten

2009-01-01

Technological developments and the trend to go higher and higher in frequency give rise to the need for true space–time rain field models for testing the dynamics of fade countermeasures. There are many models that capture the spatial correlation of rain fields. Worth mentioning are those models based on cell ensembles. However, the rain rate fields created in this way need the introduction of the time variable to reproduce their dynamics. In this paper, we have concentrated on ad...

Determining hydrological changes in a small Arctic treeline basin using cold regions hydrological modelling and a pseudo-global warming approach

Science.gov (United States)

Krogh, S. A.; Pomeroy, J. W.

2017-12-01

Increasing temperatures are producing higher rainfall ratios, shorter snow-covered periods, permafrost thaw, more shrub coverage, more northerly treelines and greater interaction between groundwater and surface flow in Arctic basins. How these changes will impact the hydrology of the Arctic treeline environment represents a great challenge. To diagnose the future hydrology along the current Arctic treeline, a physically based cold regions model was used to simulate the hydrology of a small basin near Inuvik, Northwest Territories, Canada. The hydrological model includes hydrological processes such as snow redistribution and sublimation by wind, canopy interception of snow/rain and sublimation/evaporation, snowmelt energy balance, active layer freeze/thaw, infiltration into frozen and unfrozen soils, evapotranspiration, horizontal flow through organic terrain and snowpack, subsurface flow and streamflow routing. The model was driven with weather simulated by a high-resolution (4 km) numerical weather prediction model under two scenarios: (1) control run, using ERA-Interim boundary conditions (2001-2013) and (2) future, using a Pseudo-Global Warming (PGW) approach based on the RCP8.5 projections perturbing the control run. Transient changes in vegetation based on recent observations and ecological expectations were then used to re-parameterise the model. Historical hydrological simulations were validated against daily streamflow, snow water equivalent and active layer thickness records, showing the model's suitability in this environment. Strong annual warming ( 6 °C) and more precipitation ( 20%) were simulated by the PGW scenario, with winter precipitation and fall temperature showing the largest seasonal increase. The joint impact of climate and transient vegetation changes on snow accumulation and redistribution, evapotranspiration, active layer development, runoff generation and hydrograph characteristics are analyzed and discussed.

Satellite passive microwave rain measurement techniques for land and ocean

Science.gov (United States)

Spencer, R. W.

1985-01-01

Multiseasonal rainfall was found to be measurable over land with satellite passive microwave data, based upon comparisons between Nimbus 7 Scanning Multichannel Microwave Radiometer (SMME) brightness temperatures (T sub B) and operational WSR-57 radar rain rates. All of the SMMR channels (bipolarized 37, 21, 18, 10.7, and 6.6. GHz T sub B) were compared to radar reflectivities for 25 SMMR passes and 234 radar scans over the U.S. during the spring, summer, and fall of 1979. It was found that the radar rain rates were closely related to the difference between 37 and 21 GHz T sub B. This result is due to the volume scattering effects of precipitation which cause emissivity decreases with frequency, as opposed to emissive surfaces (e.g., water) whose emissivities increase with frequency. Two frequencies also act to reduce the effects of thermometric temperature variations on T sub B to a miminum. During summer and fall, multiple correlation coefficients of 0.80 and 0.75 were obtained. These approach the limit of correlation that can be expected to exist between two very different data sources, especially in light of the errors attributable to manual digitization of PPI photographs of variable quality from various operational weather radar not calibrated for research purposes. During the spring, a significantly lower (0.63) correlation was found. This poorer performance was traced to cases of wet, unvegetated soil being sensed at the lower frequencies through light rain, partly negating the rain scattering signal.

RAIN: A Bio-Inspired Communication and Data Storage Infrastructure.

Science.gov (United States)

Monti, Matteo; Rasmussen, Steen

2017-01-01

We summarize the results and perspectives from a companion article, where we presented and evaluated an alternative architecture for data storage in distributed networks. We name the bio-inspired architecture RAIN, and it offers file storage service that, in contrast with current centralized cloud storage, has privacy by design, is open source, is more secure, is scalable, is more sustainable, has community ownership, is inexpensive, and is potentially faster, more efficient, and more reliable. We propose that a RAIN-style architecture could form the backbone of the Internet of Things that likely will integrate multiple current and future infrastructures ranging from online services and cryptocurrency to parts of government administration.

Corresponding Relation between Warm Season Precipitation Extremes and Surface Air Temperature in South China

Institute of Scientific and Technical Information of China (English)

SUN; Wei; LI; Jian; YU; Ru-Cong

2013-01-01

Hourly data of 42 rain gauges over South China during 1966–2005 were used to analyze the corresponding relation between precipitation extremes and surface air temperature in the warm season(May to October).The results show that below 25℃,both daily and hourly precipitation extremes in South China increase with rising temperature.More extreme events transit to the two-time Clausius-Clapeyron(CC)relationship at lower temperatures.Daily as well as hourly precipitation extremes have a decreasing tendency nearly above 25℃,among which the decrease of hourly extremes is much more significant.In order to investigate the efects of rainfall durations,hourly precipitation extremes are presented by short duration and long duration precipitation,respectively.Results show that the dramatic decrease of hourly rainfall intensities above 25℃ is mainly caused by short duration precipitation,and long duration precipitation extremes rarely occur in South China when surface air temperature surpasses 28℃.

Determination of Cs-134 and Cs-137 rain water samples

International Nuclear Information System (INIS)

Lima, M.F.; Mazzilli, B.

1988-01-01

In order to setting an environmental monitoring program at IPEN, was developed a fast and simple methodology for concentration of Cs-134 and Cs-137 in rain water. This procedure consists in the precipitation of cesium and others cathions of its family (NH 4 + , K + and Rb + ) by ammonium molybdophosphate. The measures of the desintegration rates of Cs-134 and Cs-137 was done by gamma spectrometry in a Ge(Li) detector. After setting up the ideal experimental conditions, the procedure was used to analyze four samples of rain water. (author) [pt

Influence of simulated acid rain on the flowering dogwood (Cornus florida) leaf surface

Energy Technology Data Exchange (ETDEWEB)

Brown, D.A. (Auburn Univ., AL (United States)); Windham, M.T.; Trigiano, R.N. (Tennessee Univ., Knoxville, TN (United States)); Anderson, R.L. (United States Dept. of Agriculture, Asheville, NC (United States))

1994-01-01

Acidic rainfall has the potential to influence anthracnose incidence and severity in flowering dogwood (Cornus florida L.) of the eastern United States. One-year-old, nursery-grown flowering dogwood seedlings were exposed to 1 cm of simulated rain 10 times over a 42-day period in 1990. Simulated rains were composed of a mixture of salts typical of ambient rainfall in the eastern United States and pH was adjusted to 5.5, 4.5, 3.5, and 2.5 with sulfuric and nitric acids. Samples were cut from the leaf tip, margin, and midvein of rain-treated trees and prepared for scanning electron microscopy. Cuticular cracking, desiccation, and erosion of trichrome surfaces were observed with decreasing pH for all samples. Cuticular erosion due to acid rain has the potential to predispose dogwoods in the eastern United States to anthracnose caused by Discula destructiva sp.nov. (Red.) and an unnamed Discula sp. 25 refs., 4 figs.

Controlled soil warming powered by alternative energy for remote field sites.

Science.gov (United States)

Johnstone, Jill F; Henkelman, Jonathan; Allen, Kirsten; Helgason, Warren; Bedard-Haughn, Angela

2013-01-01

Experiments using controlled manipulation of climate variables in the field are critical for developing and testing mechanistic models of ecosystem responses to climate change. Despite rapid changes in climate observed in many high latitude and high altitude environments, controlled manipulations in these remote regions have largely been limited to passive experimental methods with variable effects on environmental factors. In this study, we tested a method of controlled soil warming suitable for remote field locations that can be powered using alternative energy sources. The design was tested in high latitude, alpine tundra of southern Yukon Territory, Canada, in 2010 and 2011. Electrical warming probes were inserted vertically in the near-surface soil and powered with photovoltaics attached to a monitoring and control system. The warming manipulation achieved a stable target warming of 1.3 to 2 °C in 1 m(2) plots while minimizing disturbance to soil and vegetation. Active control of power output in the warming plots allowed the treatment to closely match spatial and temporal variations in soil temperature while optimizing system performance during periods of low power supply. Active soil heating with vertical electric probes powered by alternative energy is a viable option for remote sites and presents a low-disturbance option for soil warming experiments. This active heating design provides a valuable tool for examining the impacts of soil warming on ecosystem processes.

Controlled soil warming powered by alternative energy for remote field sites.

Directory of Open Access Journals (Sweden)

Jill F Johnstone

Full Text Available Experiments using controlled manipulation of climate variables in the field are critical for developing and testing mechanistic models of ecosystem responses to climate change. Despite rapid changes in climate observed in many high latitude and high altitude environments, controlled manipulations in these remote regions have largely been limited to passive experimental methods with variable effects on environmental factors. In this study, we tested a method of controlled soil warming suitable for remote field locations that can be powered using alternative energy sources. The design was tested in high latitude, alpine tundra of southern Yukon Territory, Canada, in 2010 and 2011. Electrical warming probes were inserted vertically in the near-surface soil and powered with photovoltaics attached to a monitoring and control system. The warming manipulation achieved a stable target warming of 1.3 to 2 °C in 1 m(2 plots while minimizing disturbance to soil and vegetation. Active control of power output in the warming plots allowed the treatment to closely match spatial and temporal variations in soil temperature while optimizing system performance during periods of low power supply. Active soil heating with vertical electric probes powered by alternative energy is a viable option for remote sites and presents a low-disturbance option for soil warming experiments. This active heating design provides a valuable tool for examining the impacts of soil warming on ecosystem processes.

The Warm Plasma Composition in the Inner Magnetosphere during 2012-2015

Science.gov (United States)

Jahn, J. M.; Goldstein, J.; Reeves, G. D.; Fernandes, P. A.; Skoug, R. M.; Larsen, B.; Spence, H. E.

2017-12-01

Ionospheric heavy ions play an important role in the dynamics of Earth's magnetosphere. The greater mass and gyro radius of ionospheric oxygen differentiates its behavior from protons at the same energies. Oxygen may have an impact on tail reconnection processes, and it can at least temporarily dominate the energy content of the ring current during geomagnetic storms. At sub-keV energies, multi-species ion populations in the inner magnetosphere form the warm plasma cloak, occupying the energy range between the plasmasphere and the ring current. Lastly, cold lighter ions from the mid-latitude ionosphere create the co-rotating plasmasphere whose outer regions can interact with the plasma cloak, plasma sheet, ring current, and outer electron belt. In this paper we present a statistical view of warm, cloak-like ion populations in the inner magnetosphere, contrasting in particular the warm plasma composition during quiet and active times. We study the relative abundances and absolute densities of warm plasma measured by the Van Allen Probes, whose two spacecraft cover the inner magnetosphere from plasmaspheric altitudes close to Earth to just inside geostationary orbit. We observe that warm (> 30 eV) oxygen is most abundant closer to the plasmasphere boundary whereas warm hydrogen dominates closer to geostationary orbit. Warm helium is usually a minor constituent, but shows a noticeable enhancement in the near-Earth dusk sector.

Numerical modeling of atmospheric washout processes

International Nuclear Information System (INIS)

Bayer, D.; Beheng, K.D.; Herbert, F.

1987-01-01

For the washout of particles from the atmosphere by clouds and rain one has to distinguish between processes which work in the first phase of cloud development, when condensation nuclei build up in saturated air (Nucleation Aerosol Scavenging, NAS) and those processes which work at the following cloud development. In the second case particles are taken off by cloud droplets or by falling rain drops via collision (Collision Aerosol Scavenging, CAS). The physics of both processes is described. For the CAS process a numerical model is presented. The report contains a documentation of the mathematical equations and the computer programs (FORTRAN). (KW) [de

A tale of two rain gardens: Barriers and bridges to adaptive ...

Science.gov (United States)

Green infrastructure installations such as rain gardens and bioswales are increasingly regarded as viable tools to mitigate stormwater runoff at the parcel level. The use of adaptive management to implement and monitor green infrastructure projects as experimental attempts to manage stormwater has not been adequately explored as a way to optimize green infrastructure performance or increase social and political acceptance. Efforts to improve stormwater management through green infrastructure suffer from the complexity of overlapping jurisdictional boundaries, as well as interacting social and political forces that dictate the flow, consumption, conservation and disposal of urban wastewater flows. Within this urban milieu, adaptive management—rigorous experimentation applied as policy—can inform new wastewater management techniques such as the implementation of green infrastructure projects. In this article, we present a narrative of scientists and practitioners working together to apply an adaptive management approach to green infrastructure implementation for stormwater management in Cleveland, Ohio. In Cleveland, contextual legal requirements and environmental factors created an opportunity for government researchers, stormwater managers and community organizers to engage in the development of two distinct sets of rain gardens, each borne of unique social, economic and environmental processes. In this article we analyze social and political barriers to app

Evaluation of the value of radar QPE data and rain gauge data for hydrological modeling

DEFF Research Database (Denmark)

He, Xin; Sonnenborg, Torben Obel; Refsgaard, Jens Christian

2013-01-01

rainfall and subsequently the simulated hydrological responses. A headwater catchment located in western Denmark is chosen as the study site. Two hydrological models are built using the MIKE SHE code, where they have identical model structures expect for the rainfall forcing: one model is based on rain...... value of the extra information from radar when rain gauge density decreases; however it is not able to sustain the level of model performance preceding the reduction in number of rain gauges......Weather radar-based quantitative precipitation estimation (QPE) is in principle superior to the areal precipitation estimated by using rain gauge data only, and therefore has become increasingly popular in applications such as hydrological modeling. The present study investigates the potential...

G-warm inflation

Science.gov (United States)

Herrera, Ramón

2017-05-01

A warm inflationary universe in the context of Galileon model or G-model is studied. Under a general formalism we study the inflationary dynamics and the cosmological perturbations considering a coupling of the form G(phi,X)=g(phi) X. As a concrete example, we consider an exponential potential together with the cases in which the dissipation and Galilean coefficients are constants. Also, we study the weak regime given by the condition RR+3gHdot phi. Additionally, we obtain constraints on the parameters during the evolution of G-warm inflation, assuming the condition for warm inflation in which the temperature T>H, the conditions or the weak and strong regimes, together with the consistency relation r=r(ns) from Planck data.

A Unified Statistical Rain-Attenuation Model for Communication Link Fade Predictions and Optimal Stochastic Fade Control Design Using a Location-Dependent Rain-Statistic Database

Science.gov (United States)

Manning, Robert M.

1990-01-01

A static and dynamic rain-attenuation model is presented which describes the statistics of attenuation on an arbitrarily specified satellite link for any location for which there are long-term rainfall statistics. The model may be used in the design of the optimal stochastic control algorithms to mitigate the effects of attenuation and maintain link reliability. A rain-statistics data base is compiled, which makes it possible to apply the model to any location in the continental U.S. with a resolution of 0-5 degrees in latitude and longitude. The model predictions are compared with experimental observations, showing good agreement.

Preliminary information on studies of radioactive rain

Energy Technology Data Exchange (ETDEWEB)

Fernando, A A; Beltran, V; Brody, T A; Lezama, H; Moreno, A; Tejera, M A; Vazquer, B

1956-01-01

Data on radioactive rain, which were obtained by the gummed leaf method and by collection in a free surface of water are presented. The experimental methods are described. Some conclusions are obtained on the relative efficiency of the two methods and their relations to atmospheric precipitation.