WorldWideScience

Sample records for rain researchniva contributions

  1. Acid rain research[NIVA contributions to ACID REIGN '95? Conference in Gothenburg, Sweden, 26-30 June 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The conference dealt with various sources, aspects and present and future consequences of pollution, particularly acid precipitation on the environment especially on the terrestrial and aquatic parts, with the focus on acidification. Surveys of the extent of the problems were presented. Various methods of reversing the effects are dealt with. Much attention was focused on various water systems such as rivers, lakes, surface waters and ground water and consequences of pollution chemically, geologically, biologically and botanically. The problems of global warming and changes were also focused upon. The origins of pollutants were discussed.

  2. Acid rain research[NIVA contributions to ACID REIGN '95? Conference in Gothenburg, Sweden, 26-30 June 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The conference dealt with various sources, aspects and present and future consequences of pollution, particularly acid precipitation on the environment especially on the terrestrial and aquatic parts, with the focus on acidification. Surveys of the extent of the problems were presented. Various methods of reversing the effects are dealt with. Much attention was focused on various water systems such as rivers, lakes, surface waters and ground water and consequences of pollution chemically, geologically, biologically and botanically. The problems of global warming and changes were also focused upon. The origins of pollutants were discussed.

  3. 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....

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Factors contributing to the hydrologic effectiveness of a rain garden network (Cincinnati OH USA)

    Science.gov (United States)

    Infiltrative rain gardens add retention capacity to sewersheds, yet, their capacity for detention and redistribution of stormwater runoff is dynamic and often unverified by monitoring. Over a 4-year period, we tracked whole system water fluxes in a two-tier rain garden network, a...

  6. Acid Rain Contribution from Pesticide Distribution to Rice Farmers in Pati Regency

    Science.gov (United States)

    Qosim, Ahmad; Anies; Sunoko, Henna Rya

    2018-02-01

    Productivity rate of rice fields in Regency has been in a surplus condition annually. The fields have produced 7 to 8 tons per hectare, making the total annual rate of 600 tons. The regency, therefore, is considered to be capable of fulfilling its own need for rice and to contribute significantly to the rice needs in Central Java Province. Agriculture coexists with the presence of pesticides. While helping the farmers to combat the plant diseases, pesticides have still been greatly necessary by the local farmers. Distribution by means of transportation devices plays an important role for the dissemination of the pesticides from the producers to their end users. Problem arises due to emission produced during the transportation activities. Transportation emits SO2 as the major contributor to acid rain. To make worse, application in practice by the farmers also emit the similar substance. Annual use of pesticides in Pati Regency has reached 605 tons with SO2 emission of 13,697 kg. It is recommended that distribution management and selection of pesticides are performed by applying an integrated pest control in order to reduce the pesticide emission.

  7. Contribution and loading estimation of organochlorine pesticides from rain and canopy throughfall to runoff in an urban environment.

    Science.gov (United States)

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

    2011-01-30

    Concentrations of OCPs in rain, canopy throughfall, and runoff water were measured in the Beijing metropolitan area during the rainy seasons from 2006 to 2007. This study was conducted to calculate the fluxes of OCPs in rain and canopy throughfall, as well as their contributions to runoff. At urban sites, the contribution of HCB and ΣHCHs from rainfall accounted for approximately 50% of the mass in runoff. At the site with significant coverage of landscaping trees, the HCB, ΣHCHs, and ΣDDTs from the net canopy throughfall accounted for approximately 10% of the mass in the runoff. Based on the data obtained in this study, loadings of OCPs (in μg) in rain, net canopy throughfall, and runoff water were calculated. The input of OCPs from rain and canopy throughfall water accounted for a significant portion of urban runoff. In cities undergoing rapid urban sprawl, monitoring and control of the transport of OCPs in urban runoff are essential for effective control of environmental hazards in surface water bodies. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Contribution to the study of gaseous molecular iodine washout by natural rains

    International Nuclear Information System (INIS)

    Fournier-Bidoz, V.

    1991-01-01

    This study is part of researches about nuclear accident prediction consequences on the environment. It concerns transfering of molecular gaseous iodine into liquids and especially precipitation scavenging below the cloud (washout). Bibliographic data directly concerned with this study (iodine's aqueous chemistry, aqueous to gaseous phases transfer) and also with its global frame-work (atmospheric release from a nuclear reactor in accidental situation and the behaviour of atmospheric iodine) are presented. Several experimental approaches have been performed in laboratory and on field. An aqueous to gaseous phase transfer simulator allowed us to isolate parameters involved in absorption and desorption of the halogen. Field experiments permit to quantify dry deposition on different solutions and to get a better insight of the phenomenon. Extrapolation of the whole results to precipitation scavenging of gaseous iodine I 2 by natural rains suggests that the process is an irreversible one. Washout rate values acquired during rainy experiments with molecular iodine emission or in a laboratory rainfall simulator agree with literatures data relative to irreversibility. However and even if reversibility was efficient it was not possible to clearly exhibit it according to experimental conditions. Moreover, the analytical iodine method which leads to a good experimental study has been presented

  9. 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.

  10. 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.

  11. Assessment of the contribution of sewer deposits to suspended solids loads in combined sewer systems during rain events.

    Science.gov (United States)

    Hannouche, A; Chebbo, G; Joannis, C

    2014-04-01

    Within the French observatories network SOERE "URBIS," databases of continuous turbidity measurements accumulating hundreds of events and many dry weather days are available for two sites with different features (Clichy in Paris and Ecully in Lyon). These measurements, converted into total suspended solids (TSS) concentration using TSS-turbidity relationships and combined with a model of runoff event mean concentration, enable the assessment of the contribution of sewer deposits to wet weather TSS loads observed at the outlet of the two watersheds. Results show that the contribution of sewer deposits to wet weather suspended solid's discharges is important but variable (between 20 and 80 % of the mass at the outlet depending on the event), including a site allegedly free of (coarse) sewer deposits. The uncertainties associated to these results are assessed too.

  12. 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).

  13. 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…

  14. 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…

  15. 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)…

  16. 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.

  17. 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…

  18. 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)

  19. Contribution of nitrogen oxides to the acidification of rain (part 2). Evaluation of nitrate production mechanisms in a droplet by fog chemical model simulation

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, A. (and others) (CRIEPI, Komae-shi (Japan). Komae Research Lab.)

    1994-01-01

    The fog chemical model developed in the previous work was applied to various types of fog. Simulated results of Cl[sup -], NO[sub 3][sup -] and SO[sub 4][sup 2-] concentrations in fogwater by the fog chemical model almost agreed with observed values in case the fog total ionic concentration was above 1000 [mu]eg/1. The chemical compositions of ideal water droplets formed under various atmospheric conditions based on observation data were predicted by the fog chemical model. About 80% of HNO[sub 3] and HCl in the atmosphere were scavenged by the droplets in all the cases. SO[sub 2] scavenging ratio by a droplet was dependent mainly on the pH of the droplet. When the droplet pH was decreased by dissolution of HNO[sub 3] and HCl, aqueous phase sulfate production was inhibited by decrease of SO[sub 2] solubility in the droplet. Contribution of HNO[sub 3] in the atmosphere was larger than that of SO[sub 2] to the acidification of highly acidic fogwater observed in Kanto district. In addition, HCl was considered to play an important role, as well as HNO[sub 3], in the acidification of fogwater.

  20. 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.

  1. 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...

  2. 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…

  3. 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.

  4. 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).

  5. 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.

  6. 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...

  7. Contamination of foods by radioactive rains

    Energy Technology Data Exchange (ETDEWEB)

    Obo, F; Wakamatsu, C; Nakae, Y; Higasayama, S

    1955-01-01

    The radioactivities of various vegetable foods contaminated by radioactive rains in May, 1954, in the Kagoshima Area were detected. Tea showed especially high radioactivities which could be extracted with hot water. Radioactive Nb, Zr, Hf, Ce, Y, Pr, and La were detected in the hot water extractions of tea by ion-exchange chromatography. The partial contribution of /sup 40/K in these radioactive vegetables was critically examined.

  8. Industrial ecotoxicology "acid rain".

    Science.gov (United States)

    Astolfi, E; Gotelli, C; Higa, J

    1986-01-01

    The acid rain phenomenon was studied in the province of Cordoba, Argentina. This study, based on a previously outlined framework, determined the anthropogenic origin of the low pH due to the presence of industrial hydrochloric acid wastage. This industrial ecotoxicological phenomenon seriously affected the forest wealth, causing a great defoliation of trees and shrubs, with a lower effect on crops. A survey on its effects on human beings has not been carried out, but considering the corrosion caused to different metals and its denouncing biocide effect on plants and animals, we should expect to find some kind of harm to the health of the workers involved or others engaged in farming, and even to those who are far away from the polluting agent.

  9. Methane rain on Titan

    Science.gov (United States)

    Toon, Owen B.; Mckay, Christopher P.; Courtin, Regis; Ackerman, Thomas P.

    1988-01-01

    The atmosphere of Titan is characterized by means of model computations based on Voyager IRIS IR spectra and published data from laboratory determinations of absorption coefficients and cloud refractive indices. The results are presented in tables and graphs, and it is pointed out that the presence of Ar is not required in the model. Particular attention is given to the role of CH4, which is found to form patchy clouds (with particle radii of 50 microns or greater and visible/IR optical depths of 2-5) at altitudes up to about 30 km. The mechanisms by which such rain-sized particles could form are discussed, and it is suggested that the observed 500-600/cm spectrum is affected much less by the CH4 clouds than by H2 or variations in the temperature of the high-altitude haze.

  10. 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…

  11. 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...

  12. 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

  13. Acidification and Acid Rain

    Science.gov (United States)

    Norton, S. A.; Veselã½, J.

    2003-12-01

    endangers the existing biota. Concerns about acid (or acidic) rain in its modern sense were publicized by the Swedish soil scientist Svante Odén (1968). He argued, initially in the Swedish press, that long-term increases in the atmospheric deposition of acid could lower the pH of surface waters, cause a decline in fish stocks, deplete soils of nutrients, and accelerate damage to materials. By the 1970s, acidification of surface waters was reported in many countries in Europe as well as in North America. The late twentieth-century rush to understand the impact of acid rain was driven by: (i) reports of damaged or threatened freshwater fisheries and (ii) damaged forests. Perhaps the earliest linkage between acidic surface water and damage to fish was made by Dahl (1921) in southern Norway. There, spring runoff was sufficiently acidic to kill trout. It was not until the 1970s that a strong link was established between depressed pH, mobilization of aluminum from soil, and fish status ( Schofield and Trojnar,1980). The relationship between acidification of soils and forest health started with hypotheses in the 1960s and has slowly developed. Acid rain enhances the availability of some nutrients (e.g., nitrogen), and may either enhance or diminish the availability of others (e.g., calcium, magnesium, potassium, and phosphorus). Damage to anthropogenic structures, human health, and visibility have also raised concerns. The history of these early developments was summarized by Cowling (1982). Since the 1970s, sulfur and nitrogen emissions to the atmosphere have been reduced by 50-85% and 0-30%, respectively, both in North America and Europe. The emission reductions have occurred as a consequence of knowledge gained and economic factors. While recovery of water quality is underway in some areas, problems of acidification persist, and are now complicated by the effects of climate change ( Schindler, 1997).

  14. 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.

  15. 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 ...

  16. [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.

  17. The combined effect of wind and rain on interrill erosion processes

    International Nuclear Information System (INIS)

    Erpul, G.; Gabriels, D.; Norton, L.D.

    2004-01-01

    flow-driven process begins to transport the detached soil particles. This is different from the approach of recent interrill erosion models that soil detached by the rain splash will be subsequently transported by overland flow. The results of the study showed that, when compared to the contribution of the flow-driven transport, the contribution of the rain splash transport was significant to the extent that it should not be neglected in accurately predicting water erosion from interrill areas under wind-driven rains

  18. 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.

  19. 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

  20. 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.

  1. Rain, Snow, and Spring Runoff Revisited.

    Science.gov (United States)

    Bohren, Craig F.

    1995-01-01

    Explores the theory behind the correlation between warm rain, rapid snowmelt, and the subsequent runoff using the concepts of enthalpy, thermal transfer, and energy transfer. Concludes that rapid runoff is not a consequence of rain per se but of the high humidities associated with the rain. (JRH)

  2. 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

  3. 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, ...

  4. 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

  5. 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

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

    Science.gov (United States)

    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.

  7. 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.)

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Estimate of rain evaporation rates from dual-wavelength lidar measurements: comparison against a model analytical solution

    Science.gov (United States)

    Lolli, Simone; Di Girolamo, Paolo; Demoz, Belay; Li, Xiaowen; Welton, Ellsworth J.

    2018-04-01

    Rain evaporation significantly contributes to moisture and heat cloud budgets. In this paper, we illustrate an approach to estimate the median volume raindrop diameter and the rain evaporation rate profiles from dual-wavelength lidar measurements. These observational results are compared with those provided by a model analytical solution. We made use of measurements from the multi-wavelength Raman lidar BASIL.

  13. 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…

  14. 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...

  15. 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…

  16. 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.

  17. Scale Dependence of Spatiotemporal Intermittence of Rain

    Science.gov (United States)

    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.

  18. Warm Rain Processes Over the Tropical Oceans and Implications on Climate Change

    Science.gov (United States)

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

    2004-01-01

    In this talk, we will first show results from TRMM regarding the characteristics of warm rains over the tropical oceans, and the dependence of rate of warm rain production on sea surface temperature. Results lead to the hypothesis that warm rain production efficiency, i.e., autoconversion, may be increased in a warm climate. We use the GEOS-II GCM to test this hypothesis. Our modeling results show that in a climate with increased rate of autoconversion, the total rain amount is increased, with warm rain contributing to a larger portion of the increase. The abundant rainout of warm precipitation at middle to low levels causes a reduction of high cloud cover due to the depletion of water available for ice-phase rain production. As a result, more isolated, but more intense penetrative convection develops. Results also show that increased autoconversion reduces the convective adjustment time scale tends, implying a faster recycling of atmospheric water. Most interestingly, the increased low level heating associated with warm rain leads to more energetic Madden and Julian oscillations in the tropics, with well-defined eastward propagation. While reducing the autoconversion leads to an abundant mix of westward and eastward tropical disturbance on daily to weekly time scales. The causes of the sensitivity of the dynamical regimes to the microphysics parameterization in the GCM will be discussed.

  19. 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.

  20. 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

  1. Analysis of warm convective rain events in Catalonia

    Science.gov (United States)

    Ballart, D.; Figuerola, F.; Aran, M.; Rigo, T.

    2009-09-01

    Between the end of September and November, events with high amounts of rainfall are quite common in Catalonia. The high sea surface temperature of the Mediterranean Sea near to the Catalan Coast is one of the most important factors that help to the development of this type of storms. Some of these events have particular characteristics: elevated rain rate during short time periods, not very deep convection and low lightning activity. Consequently, the use of remote sensing tools for the surveillance is quite useless or limited. With reference to the high rain efficiency, this is caused by internal mechanisms of the clouds, and also by the air mass where the precipitation structure is developed. As aforementioned, the contribution of the sea to the air mass is very relevant, not only by the increase of the big condensation nuclei, but also by high temperature of the low layers of the atmosphere, where are allowed clouds with 5 or 6 km of particles in liquid phase. In fact, the freezing level into these clouds can be detected by -15ºC. Due to these characteristics, this type of rainy structures can produce high quantities of rainfall in a relatively brief period of time, and, in the case to be quasi-stationary, precipitation values at surface could be very important. From the point of view of remote sensing tools, the cloud nature implies that the different tools and methodologies commonly used for the analysis of heavy rain events are not useful. This is caused by the following features: lightning are rarely observed, the top temperatures of clouds are not cold enough to be enhanced in the satellite imagery, and, finally, reflectivity radar values are lower than other heavy rain cases. The third point to take into account is the vulnerability of the affected areas. An elevated percentage of the Catalan population lives in the coastal region. In the central coast of Catalonia, the urban areas are surrounded by a not very high mountain range with small basins and

  2. 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.

  3. 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...

  4. 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

  5. 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...

  6. 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 ...

  7. 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.

  8. 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

  9. 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.)

  10. 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.)

  11. 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

  12. 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 ...

  13. 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...

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Rain from South and snow from North

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Y

    1954-12-01

    Detection of nuclear explosions by various methods including observations of fission product activity in the atmosphere is discussed. Deposition of 750 cpm on a vase-line coated paper (30 x 30 cm) on May 13 to 16, 1954 was recorded. Eighty-six thousand cpm/1 was observed in rain at Kyoto on May 14, apparently from the May 5 test at Bikini.

  3. 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)

  4. 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

  5. Acid Rain Analysis by Standard Addition Titration.

    Science.gov (United States)

    Ophardt, Charles E.

    1985-01-01

    The standard addition titration is a precise and rapid method for the determination of the acidity in rain or snow samples. The method requires use of a standard buret, a pH meter, and Gran's plot to determine the equivalence point. Experimental procedures used and typical results obtained are presented. (JN)

  6. 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.

  7. 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...

  8. 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 $

  9. 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.

  10. 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

  11. 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...

  12. 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.

  13. Effects of rare earth and acid rain pollution on plant chloroplast ATP synthase and element contents at different growth stages.

    Science.gov (United States)

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

    2018-03-01

    Combined rare earth and acid rain pollution has become a new environmental problem, seriously affecting plant survival. The effects of these two kinds of pollutants on plant photosynthesis have been reported, but the micro mechanisms are not very clear. In this research, we studied the effects of lanthanum [La(III), 0.08, 1.20 and 2.40 mM] and acid rain (pH value = 2.5, 3.5 and 4.5) on the ATPase activity and gene transcription level and the functional element contents in rice leaf chloroplasts. The results showed that the combined 0.08 mM La(III) and pH 4.5 acid rain increased the ATPase activity and gene transcription level as well as contents of some functional elements. But other combined treatments of acid rain and La(III) reduced the ATPase activity and gene transcription level as well as functional element contents. The change magnitude of the above indexes at rice booting stage was greater than that in seedling stage or grain filling stage. These results reveal that effects of La(III) and acid rain on ATPase activity and functional element contents in rice leaf chloroplasts are related to the combination of La(III) dose and acid rain intensity and the plant growth stage. In addition, the changes in the ATPase activity were related to ATPase gene transcription level. This study would provide a reference for understanding the microcosmic mechanism of rare earth and acid rain pollution on plant photosynthesis and contribute to evaluate the possible environmental risks associated with combined La(III) and acid rain pollution. The effects of La(III) and acid rain on activity and gene transcription level of rice chloroplast ATPase and contents of functional elements were different at different growth stages. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. Rain VM: Portable Concurrency through Managing Code

    OpenAIRE

    Brown, Neil C.C.

    2006-01-01

    A long-running recent trend in computer programming is the growth in popularity of virtual machines. However, few have included good support for concurrency - a natural mechanism in the Rain programming language. This paper details the design and implementation of a secure virtual machine with support for concurrency, which enables portability of concurrent programs. Possible implementation ideas of many-to-many threading models for the virtual machine kernel are discussed, and initial benchm...

  19. 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

  20. 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

  1. Estimating Rain Attenuation In Satellite Communication Links

    Science.gov (United States)

    Manning, R. M.

    1991-01-01

    Attenuation computed with help of statistical model and meteorological data. NASA Lewis Research Center Satellite Link Attenuation Model (SLAM) program QuickBASIC computer program evaluating static and dynamic statistical assessment of impact of rain attenuation on communication link established between Earth terminal and geosynchronous satellite. Application in specification, design, and assessment of satellite communication links for any terminal location in continental United States. Written in Microsoft QuickBASIC.

  2. 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.

  3. 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.

  4. Acid rain legislation and local areas

    International Nuclear Information System (INIS)

    Jones, G.H.B.

    1992-01-01

    This study explores the local economic impacts of the phase I requirements of the 1990 acid rain legislation. This legislation allows electric utilities to adopt least cost ways of reducing sulfur dioxide pollution. The impact on employment, income and size distribution of income due to a switch to low sulfur coal is examined for a selected number of high sulfur coal producing counties in southern Illinois. In order to achieve the above objectives a generalized non-survey input-output model, IMPLAN (Impact Analysis for Planning), is employed to estimate first- and second-order employment and income effects of a switch to low sulfur coal. Two models, I and II, are constructed to provide these estimates. In Model I, income is generated and adjusted to reflect income retained and spent within the four county region. In Model II, no adjustment is made for flows into and out of the region. In addition to adjustments in income, adjustments in direct employment impacts were made in both models to account for retirements. Scenarios reflecting different degrees of coal switching, low and high switching options, were examined under both models. With regards to size distribution impacts, a newly developed operational model compatible with IMPLAN and developed by Rose et al (1988) was employed. This model is a member of a class of models collectively termed extended input-output models. As in the case of employment and income, allowance was made for income generated, retained and spent within the four counties in the assessment of income distribution impacts. The findings indicate that the adverse effects of a switch to low sulfur coal under the 1990 acid rain legislation will primarily hurt the coal mining industry. Coal mining employment and income will be adversely affected. Employment and income declines in other industries in the region will be fairly slight. Second, income distribution becomes slightly more equal for the local area due to acid rain control

  5. Warm Rain Processes Over the Tropical Oceans and Implications on Climate Change: Results from TRMM and GOES GCM

    Science.gov (United States)

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

    2004-01-01

    In this talk, we will first show results from TRMM data regarding the characteristics of warm rains over the tropical oceans, and the dependence of rate of warm rain production on sea surface temperature. Results lead to the hypothesis that warm rain production efficiency, i.e., autoconversion, may be increased in a warm climate. We use the GEOS-II GCM to test this hypothesis. Our modeling results show that in a climate with increased rate of autoconversion, the total rain amount is increased, with warm rain contributing to a larger portion of the increase. The abundant rainout of warm precipitation causes a reduction of low and middle cloud amount due to rainout, and reduced high clouds due to less water vapor available for ice-phase convection. However, clod radiation feedback caused by the increased rainfall efficiency, leads to differential vertical heating/cooling producing a more unstable atmosphere, allowing, more intense, but isolated penetrative convection, with contracted anvils to develop. Results also show that increased autoconversion reduces the convective adjustment time scale, resulting in faster recycling of atmospheric water. Most interestingly, the increased low level heating associated with warm rain leads to more energetic Madden and Julian oscillations in the tropics, with well-defined eastward propagation. While reducing the autoconversion leads to an abundant mix of westward and eastward tropical disturbances on daily to weekly time scales. The crucial link of precipitation microphysical processes to climate change including the effects of aerosols will be discussed.

  6. Warm Rain Processes over the Tropical Oceans and Implications on Climate Change: Results from TRMM and GEOS GCM

    Science.gov (United States)

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

    2004-01-01

    In this talk, we will first show results from TRMM data regarding the characteristics of warm rains over the tropical oceans, and the dependence of rate of warm rain production on sea surface temperature. Results lead to the hypothesis that warm rain production efficiency, i.e., autoconversion, may be increased in a warm climate. We use the GEOS-II GCM to test this hypothesis. Our modeling results show that in a climate with increased rate of autoconversion, the total rain amount is increased, with warm rain contributing to larger portion of the increase. The abundant rainout of warm precipitation causes a reduction of low and middle cloud amount due to rainout, and reduced high clouds due to less water vapor available for ice-phase convection. However, clod radiation feedback caused by the increased rainfall efficiency, leads to differential vertical heating/cooling producing a more unstable atmosphere, allowing, more intense, but isolated penetrative convection, with contracted anvils to develop. Results also show that increased autoconversion reduces the convective adjustment time scale, resulting in faster recycling of atmospheric water. Most interestingly, the increased low level heating associated with warm rain leads to more energetic Madden and Julian oscillations in the tropics, with well-defined eastward propagation. While reducing the autoconversion leads to an abundant mix of westward and eastward tropical disturbances on daily to weekly time scales. The crucial link of precipitation microphysical processes to climate change including the effects of aerosols will be discussed.

  7. Technological options for acid rain control

    International Nuclear Information System (INIS)

    Princiotta, F.T.; Sedman, C.B.

    1993-01-01

    The paper discusses technological options for acid rain control. Compliance with Title IV of the Clean Air Act Amendments of 1990 will require careful scrutiny of a number of issues before selecting control options to reduce sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions. One key consideration is the effect of fuel switching or control technology upon the existing dust collector, with additional air toxics legislation looming ahead. A number of likely SO2 and NOx retrofit technologies and estimated costs are presented, along with results of retrofit case studies. New hybrid particulate controls are also being developed to meet future requirements

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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

  10. 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...

  11. Strategies for controlling acid rain: economic considerations

    International Nuclear Information System (INIS)

    Forster, B.A.; Crocker, T.D.

    1992-01-01

    There are two competing approaches to reducing pollution such as the acid rain precursors SOsub(2) and NOsub(x). In the command and control approach, pollution control legislation may dictate the technological method by which specified pollution reductions are to be achieved. A key feature of command-and-control regulations is their inflexibility. The alternative approach relies on market mechanisms and incentives to induce firms to reduce pollution voluntarily. Economists generally prefer this approach because it permits flexibility for firms in selecting abatement methods to minimize costs. This chapter deals with qualitative issues in determining and achieving an ''optimal'' pollution level using various taxes, subsidies or quantitative restrictions. Alternative permit schemes for achieving regional pollution control are considered. Statistical studies are discussed which compare the command-and-control approach with the economic incentives approach and show that there are substantial cost differences between them in most cases. Finally, some institutional factors, that may lead to more costly acid rain control schemes being selected, are examined. A list of 61 references is appended. (UK)

  12. Annual monsoon rains recorded by Jurassic dunes.

    Science.gov (United States)

    Loope, D B; Rowe, C M; Joeckel, R M

    2001-07-05

    Pangaea, the largest landmass in the Earth's history, was nearly bisected by the Equator during the late Palaeozoic and early Mesozoic eras. Modelling experiments and stratigraphic studies have suggested that the supercontinent generated a monsoonal atmospheric circulation that led to extreme seasonality, but direct evidence for annual rainfall periodicity has been lacking. In the Mesozoic era, about 190 million years ago, thick deposits of wind-blown sand accumulated in dunes of a vast, low-latitude desert at Pangaea's western margin. These deposits are now situated in the southwestern USA. Here we analyse slump masses in the annual depositional cycles within these deposits, which have been described for some outcrops of the Navajo Sandstone. Twenty-four slumps, which were generated by heavy rainfall, appear within one interval representing 36 years of dune migration. We interpret the positions of 20 of these masses to indicate slumping during summer monsoon rains, with the other four having been the result of winter storms. The slumped lee faces of these Jurassic dunes therefore represent a prehistoric record of yearly rain events.

  13. Study of Acid Rain in Tikrit City

    Directory of Open Access Journals (Sweden)

    Khaled H. Latef

    2013-04-01

    Full Text Available A study of the degree of acidity  for the precipitation in four different sites in Tikrit city was done  for the period from 1-February to 1-April/2007 which is the period of rains in this year.      Chemical tests included (pH as the direct indicator of the degree of acidity ,and the concentration of sulphates (SO4-2 and nitrates ( NO3- as indirect indicator.      The (pH range was (5.56-6.4 which indicates the presence of acid rain in the area under study . (SO4-2 concentrations range was (88-223mg/l while  ( NO3- concentrations range was (80-170mg/l.      The wind velocity ,temperature, and humidity during the sample collection period ranged (2.25-4m/s, (1-260C, (22%-90% respectively

  14. Acid rain compliance: Options, facts, and findings

    International Nuclear Information System (INIS)

    Knutson, K.S.; Metzroth, L.F.; Radjef-Jenatton, M.

    1991-01-01

    On January 1, 1995, those utilities affected during the Phase 1 implementation of the amended Clean Air Act will be required to comply with new clean air standards. During the next three years leading up to that date, in order to achieve compliance, those companies need to not only decide on a strategy but also implement a plan. To date very few clear-cut compliance decisions have been made. The reasons for the uncertainty center on future fuel prices and the prospects for more efficient and lower cost FGD systems. Many utility planners look at today's coal market and find it hard to believe that prices for some specialty coals, particularly ultra-low sulfur coals, will be higher than the tremendous costs associated with the development of an FGD system. With that in mind, it comes as no surprise that coal switching has been regarded as the least cost choice among even the largest sulfur emitting companies in the country. However, if companies continue to make least cost decisions based on today's coal market, the US coal and utility industries could be in for some disruptive times ahead. While no paper can completely address the enormous complexity surrounding acid rain compliance, this paper addresses some of the broad issues which result from compliance activity and summarizes the findings outlined in RDI's four volume report, the Acid Rain Handbook

  15. Acid rain still plaguing lakes and loons

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    Acid rain monitoring began more than two decades ago by Environment Canada and recent numbers indicate that acid levels in the inland waters barely respond to the reductions in sulphur dioxide (SO 2 ). Under the Canada-U.S. Air Quality Agreement, both countries have committed to reduce SO 2 emissions by 50 per cent over 1980 levels and to reduce nitrogen oxide emissions. Although Canada's goal for SO 2 reductions was achieved in 1994, the nitrogen oxide emissions remained relatively constant. A study of 152 lakes in southeastern Canada indicated that the lakes are only 41 per cent less acidic than they were 20 years ago. The area studied is more vulnerable since it received more acid rain than any other part of the country and the granite bedrock of the Canadian Shield shows a weakness in neutralizing ability. The acidification has caused declines in the populations of fish and invertebrate which loons rely on to survive. A volunteer-based program called Canadian Lakes Loon Survey supported by Environment Canada and other partners began annual monitoring of the breeding success of loons on about 800 lakes. The results showed a decline in the proportion of successful breeding between 1981 and 1997. The decline was more pronounced where the acid level was greatest. Near Sudbury, Ontario, where the emissions of SO 2 declined dramatically, invertebrates started reappearing and fish populations were successfully re-established

  16. Effects of simulated acid rain on vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Ferenbaugh, R.W.

    1974-01-01

    Experiments were performed to determine the effects of simulated acid rain on Chenopodium quinoa, Hordeum vulgare and Phaseolus vulgaris. Because of differential species' susceptibility, detailed experiments were conducted only on Phaseolus vulgaris. Acid rain was simulated by spraying the plants with a hand-held atomizer. Sulfuric acid solutions covering a pH range of 1.5 to 3.5 in one half pH unit increments were used. Gross morphological effects noted at lower pH values included failure to attain normal height, necrosis and wrinkling of leaves, excessive and adventitious budding, and premature abscission of primary leaves. Histological effects included smaller cell size, a decreased amount of intercellular space, hypertrophied nuclei and nucleoli, and a reduction in the size of starch granules within the chloroplasts. Dry weight remained an approximately constant percentage of fresh weight, and chlorophyll analyses showed that both chlorophyll concentration and ratio of chlorophyll 'a' to chlorophyll 'b' also remained constant. Respirometer studies showed that, while respiration rate increased only slightly at low pH values, photosynthetic rate increased dramatically. Quantitative analyses indicated that carbohydrate content was reduced at low pH values, with starch content reduced much more than sugar content. Root biomass was also reduced at low pH values. Application of Congo red indicator solution to the acid treated tissue showed that it was being acidified to a pH of below 4. 114 references, 23 figures, 12 tables.

  17. GPM Ground Validation Southern Appalachian Rain Gauge IPHEx V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Southern Appalachian Rain Gauge IPHEx dataset was collected during the Integrated Precipitation and Hydrology Experiment (IPHEx) field...

  18. 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...

  19. Modélisation des jets diphasiques liquide vapeur et du "Rain-Out"

    OpenAIRE

    Touil , Abdellah

    2005-01-01

    This work aims at modelling flashing liquid jets. It deals particularly with velocity and diameter of droplets formed near the orifice (orifice diameters between a few millimetres and a few decimetres). The model not only calculates changes of temperature, fluid concentration, size and velocity of droplets, but also « rain-out » fraction (liquid which falls down on the ground). This work contributes to developoing tools for estimating safety distances. An experimental program allowed measurin...

  20. 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

  1. Assessing the controls of the snow energy balance and water available for runoff in a rain-an-snow environment

    Science.gov (United States)

    Adam B. Mazurkiewicz; David G. Callery; Jeffrey J. McDonnell

    2008-01-01

    Rain-on-snow (ROS) melt production and its contribution to water available for runoff is poorly understood. In the Pacific Northwest (PNW) of the USA, ROS drives many runoff events with turbulent energy exchanges dominating the snow energy balance (EB). While previous experimental work in the PNW (most notably the H.J. Andrews Experimental Forest (HJA» has quantified...

  2. 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.

  3. 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....

  4. 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.

  5. 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.

  6. 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.

  7. 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)

  8. 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 ...

  9. 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...

  10. 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)

  11. 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 ...

  12. 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,…

  13. 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...

  14. 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.

  15. 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

  16. Source diagnostics of polycyclic aromatic hydrocarbons in urban road runoff, dust, rain and canopy throughfall.

    Science.gov (United States)

    Zhang, Wei; Zhang, Shucai; Wan, Chao; Yue, Dapan; Ye, Youbin; Wang, Xuejun

    2008-06-01

    Diagnostic ratios and multivariate analysis were utilized to apportion polycyclic aromatic hydrocarbon (PAH) sources for road runoff, road dust, rain and canopy throughfall based on samples collected in an urban area of Beijing, China. Three sampling sites representing vehicle lane, bicycle lane and branch road were selected. For road runoff and road dust, vehicular emission and coal combustion were identified as major sources, and the source contributions varied among the sampling sites. For rain, three principal components were apportioned representing coal/oil combustion (54%), vehicular emission (34%) and coking (12%). For canopy throughfall, vehicular emission (56%), coal combustion (30%) and oil combustion (14%) were identified as major sources. Overall, the PAH's source for road runoff mainly reflected that for road dust. Despite site-specific sources, the findings at the study area provided a general picture of PAHs sources for the road runoff system in urban area of Beijing.

  17. Selenium speciation in acidic environmental samples: application to acid rain-soil interaction at Mount Etna volcano.

    Science.gov (United States)

    Floor, Geerke H; Iglesías, Mònica; Román-Ross, Gabriela; Corvini, Philippe F X; Lenz, Markus

    2011-09-01

    Speciation plays a crucial role in elemental mobility. However, trace level selenium (Se) speciation analyses in aqueous samples from acidic environments are hampered due to adsorption of the analytes (i.e. selenate, selenite) on precipitates. Such solid phases can form during pH adaptation up till now necessary for chromatographic separation. Thermodynamic calculations in this study predicted that a pHpH eluent that matches the natural sample pH of acid rain-soil interaction samples from Etna volcano was developed. With a mobile phase containing 20mM ammonium citrate at pH 3, selenate and selenite could be separated in different acidic media (spiked water, rain, soil leachates) in rain-soil interaction using synthetic rain based on H(2)SO(4) and soil samples collected at the flanks of Etna volcano demonstrated the dominance of selenate over selenite in leachates from samples collected close to the volcanic craters. This suggests that competitive behavior with sulfate present in acid rain might be a key factor in Se mobilization. The developed speciation method can significantly contribute to understand Se cycling in acidic, Al/Fe rich environments. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. 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.

  19. 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

  20. 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.

  1. Exploring the nonlinear cloud and rain equation

    Science.gov (United States)

    Koren, Ilan; Tziperman, Eli; Feingold, Graham

    2017-01-01

    Marine stratocumulus cloud decks are regarded as the reflectors of the climate system, returning back to space a significant part of the income solar radiation, thus cooling the atmosphere. Such clouds can exist in two stable modes, open and closed cells, for a wide range of environmental conditions. This emergent behavior of the system, and its sensitivity to aerosol and environmental properties, is captured by a set of nonlinear equations. Here, using linear stability analysis, we express the transition from steady to a limit-cycle state analytically, showing how it depends on the model parameters. We show that the control of the droplet concentration (N), the environmental carrying-capacity (H0), and the cloud recovery parameter (τ) can be linked by a single nondimensional parameter (μ=√{N }/(ατH0) ) , suggesting that for deeper clouds the transition from open (oscillating) to closed (stable fixed point) cells will occur for higher droplet concentration (i.e., higher aerosol loading). The analytical calculations of the possible states, and how they are affected by changes in aerosol and the environmental variables, provide an enhanced understanding of the complex interactions of clouds and rain.

  2. Chemical Composition of Rain Water in Lebanon

    International Nuclear Information System (INIS)

    SLIM, K.; SAAD, Z.; GHADDAR, A.; NASREDDINE, M.; KATTAN, Z.

    2000-01-01

    Samples of rainfall water were collected from fifteen stations in Lebanon during the period between October 1999 and April 2000 (the rainy season in Lebanon). Nine of these stations are distributed along the urban coastal cities, from the north to the south. The remaining 6 stations which have different altitudes ranging fom 400 m to 1200 m high are distributed in the mountainous rural areas. The concentrations of major cations (H + ,Na + , Ca 2 +, Mg 2 + and NH + 4 ) and major anions (Cl - , NO - 3 , HCO - 3 and SO 2 - 4 are determined for the first time in Lebanon. It has been found that the rain water is not acidic, due to the presence of carbonate dust particles in the atmosphere, which arise from the natural carbonate rocks, especially predominance in the mountains and internal regions of Lebanon. The high predominance of Na + and Cl - in the coastal investigated stations, is attributed to marine aerosol spray. The concentrations of SO - 4 and NO - 3 are close to the concentrations expected in typical urban areas. The correlation between the concentration of chemical species confirms the influence of natural and anthropogenic sources. (author)

  3. Utility views of acid rain legislation

    International Nuclear Information System (INIS)

    Katlic, J.E.

    1990-01-01

    The electric utilities consume almost 85% of the coal that is used in the US. The utilities as well as other industries will be seriously affected by revisions currently being considered to the Clean Air Act. We endorse the 10-year scientific National Acid Precipitation Assessment Program (NAPAP) which concludes the acid rain is not an environmental crisis but a long-term problem that needs to be addressed. The extreme views expressed by environmentalists and echoed by the media have been rendered unlikely to be correct assording to the NAPAP director. For example, the report found that the majority of North American forests are healthy. In addition, SO 2 emissions are down while coal use has doubled since the 70's. However, Congress, by considering any of the proposed Clean Air bills, is ignoring the NAPAP results. Experts from all areas are touting the need for the development of a National Energy Policy which would decrease our reliance on foreign oil and capitalize on the resources in abundance here in the United States -- like coal. The President has urged lawmakers to enact measures that would do just that. Yet the Joint Committee of Congress is marching on with revisions to a Clean Air Act that is already working. This will increase the cost of energy across all areas of industry and call a halt to the industrial recovery in this country

  4. Acid rain compliance planning using decision analysis

    International Nuclear Information System (INIS)

    Norris, C.; Sweet, T.; Borison, A.

    1991-01-01

    Illinois Power Company (IP) is an investor-owned electric and natural gas utility serving portions of downstate Illinois. In addition to one nuclear unit and several small gas and/or oil-fired units, IP has ten coal-fired units. It is easy to understand the impact the Clean Air Act Amendments of 1990 (CAAA) could have on IP. Prior to passage of the CAAA, IP formed several teams to evaluate the specific compliance options at each of the high sulfur coal units. Following that effort, numerous economic analyses of compliance strategies were conducted. The CAAA have introduced a new dimension to planning under uncertainty. Not only are many of the familiar variables uncertain, but the specific form of regulation, and indeed, the compliance goal itself is hard to define. For IP, this led them to use techniques not widely used within their corporation. This paper summarizes the analytical methods used in these analyses and the preliminary results as of July, 1991. The analysis used three approaches to examine the acid rain compliance decision. These approaches were: (1) the 'most-likely,' or single-path scenario approach; (2) a multi-path strategy analysis using the strategies defined in the single-scenario analysis; and (3) a less constrained multi-path option analysis which selects the least cost compliance option for each unit

  5. Comment on “Rain dance”

    Science.gov (United States)

    Orville, Harold D.

    A recent news brief about cloud seeding work being conducted in Cohuila, Mexico, (“Rain Dance,” Eos, July 23, 1996) contained unfounded, off-hand remarks that are a disservice to many scientists and professionals in the cloud physics and weather modification community. The news brief stated that “most previous attempts to catalyze rainfall by cloud seeding have produced inconclusive results, and almost none of the experiments have had a sound scientific basis.” The inconclusive results are primarily statistical; many outstanding scientific results have developed from the 50-year history of research into weather modification.Also, most of the work that I know about has proceeded on the scientific basis that was developed over the years by the scientific and operational communities, and it is improving with time. It is grossly inaccurate to say that almost none of the experiments have had a sound scientific basis. Improvements in technology are strengthening that scientific basis, and current physical and numerical studies being conducted in many places are improving understanding. (See reviews of the status of weather modification from the American Meteorological Society [1992] and the World Meteorological Organization [1992].)

  6. Effect of simulated acid rain on vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Ferenbaugh, R.W.

    1974-01-01

    Experiments were performed to determine the effects of simulated acid rain on Chenopodium quinoa, Hordeum vulgare and Phaseolus vulgaris. Detailed experiments were conducted only on Phaseolus vulgaris. Sulfuric acid solutions covering a pH range of 1.5 to 3.5 were used. Gross morphological effects noted at lower pH values included failure to attain normal height, necrosis and wrinkling of leaves, excessive and adventitious budding, and premature abscission of primary leaves. Histological effects included smaller cell size, a decreased amount of intercellular space, hypertrophied nuclei and nucleoli, and a reduction in the size of starch granules within the chloroplasts. Dry weight remained an approximately constant percentage of fresh weight, and chlorophyll analyses showed that both chlorophyll concentration and ratio of chlorophyll to chlorophyll also remained constant. Respirometer studies showed that respiration rate increased slightly and photosynthetic rate increased dramatically. Quantitative analyses indicated that carbohydrate content was reduced at low pH values. Root biomass was also reduced. Application of Congo red indicator solution to the acid treated tissue showed that it was being acidified to a pH of below 4. Experiments involving aspiration of control tissue in acid solutions suggest that the increase in photosynthetic rate and the decreases in carbohydrate content and root biomass were caused by an uncoupling of photophosphorylation of adenosine diphosphate. Uncoupling was probably caused by hydrogen ion interference with proton pumps associated with the electron transport chain in the light reactions of photosynthesis. 128 references. (MDF)

  7. 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.

  8. 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.

  9. Evaluation of Turf-Grass and Prairie-Vegetated Rain Gardens in a Clay and Sand Soil, Madison, Wisconsin, Water Years 2004-08

    Science.gov (United States)

    Selbig, William R.; Balster, Nicholas

    2010-01-01

    The U.S. Geological Survey, in cooperation with a consortium of 19 cities, towns, and villages in Dane County, Wis., undertook a study to compare the capability of rain gardens with different vegetative species and soil types to infiltrate stormwater runoff from the roof of an adjacent structure. Two rain gardens, one planted with turf grass and the other with native prairie species, were constructed side-by-side in 2003 at two locations with different dominant soil types, either sand or clay. Each rain garden was sized to a ratio of approximately 5:1 contributing area to receiving area and to a depth of 0.5 foot. Each rain garden, regardless of vegetation or soil type, was capable of storing and infiltrating most of the runoff over the 5-year study period. Both rain gardens in sand, as well as the prairie rain garden in clay, retained and infiltrated 100 percent of all precipitation and snowmelt events during water years 2004-07. The turf rain garden in clay occasionally had runoff exceed its confining boundaries, but was still able to retain 96 percent of all precipitation and snowmelt events during the same time period. Precipitation intensity and number of antecedent dry days were important variables that influenced when the storage capacity of underlying soils would become saturated, which resulted in pooled water in the rain gardens. Because the rooftop area that drained runoff to each rain garden was approximately five times larger than the area of the rain garden itself, evapotranspiration was a small percentage of the annual water budget. For example, during water year 2005, the maximum evapotranspiration of total influent volume ranged from 21 percent for the turf rain garden in clay to 25 percent for the turf rain garden in sand, and the minimum ranged from 12 percent for the prairie rain garden in clay to 19 percent for the prairie rain garden in sand. Little to no runoff left each rain garden as effluent and a small percentage of runoff returned to the

  10. 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.

  11. Classification system for rain fed wheat grain cultivars using artificial ...

    African Journals Online (AJOL)

    Artificial neural network (ANN) models have found wide applications, including ... of grains is essential for various applications as wheat grain industry and cultivation. In order to classify the rain fed wheat cultivars using artificial neural network ...

  12. 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.

  13. 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)

  14. 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.

  15. NOS CO-OPS Meteorological Data, Rain Fall, 6-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has Rain Fall data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). WARNING: These preliminary data have not been...

  16. Rain Garden Research at EPA's Urban Watershed Research Facility

    Science.gov (United States)

    Rain gardens are vegetated depressions designed to capture and infiltrate stormwater runoff from impervious surfaces such as roofs, parking lots, and roads. The potential benefits compared to traditional curb and gutter drainage systems include peak flow attenuation in receiving...

  17. Rain Garden Research of EPA's Urban Watershed Research Facility (Poster)

    Science.gov (United States)

    Rain gardens are vegetated depressions designed to capture and infiltrate stormwater runoff from impervious surfaces such as roofs, parking lots, and roads. The potential benefits compared to traditional curb and gutter drainage systems include peak flow attenuation in receiving ...

  18. Source diagnostics of polycyclic aromatic hydrocarbons in urban road runoff, dust, rain and canopy throughfall

    International Nuclear Information System (INIS)

    Zhang Wei; Zhang Shucai; Wan Chao; Yue Dapan; Ye Youbin; Wang Xuejun

    2008-01-01

    Diagnostic ratios and multivariate analysis were utilized to apportion polycyclic aromatic hydrocarbon (PAH) sources for road runoff, road dust, rain and canopy throughfall based on samples collected in an urban area of Beijing, China. Three sampling sites representing vehicle lane, bicycle lane and branch road were selected. For road runoff and road dust, vehicular emission and coal combustion were identified as major sources, and the source contributions varied among the sampling sites. For rain, three principal components were apportioned representing coal/oil combustion (54%), vehicular emission (34%) and coking (12%). For canopy throughfall, vehicular emission (56%), coal combustion (30%) and oil combustion (14%) were identified as major sources. Overall, the PAH's source for road runoff mainly reflected that for road dust. Despite site-specific sources, the findings at the study area provided a general picture of PAHs sources for the road runoff system in urban area of Beijing. - Urban road runoff and road dust, canopy throughfall and rain were considered as a system for diagnostics of PAH sources

  19. 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

  20. 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?

  1. 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...

  2. Rain, Rain, Go Away, Come Again Another Day. Weather Preferences of Summer Tourists in Mountain Environments

    Directory of Open Access Journals (Sweden)

    Robert Steiger

    2016-04-01

    Full Text Available Weather and climate are important factors for travel decision-making and overall tourist satisfaction. As central motivators for destination choice, they directly and indirectly influence demand patterns and can be a resource and limitation for tourism at the same time. In this paper, results of an in-situ survey of mountain summer tourists (n = 733 in the Alps in Southern Germany are presented. Respondents rated ‘rain’ as the most important aspect of weather during their holiday. During a 7-day holiday, 2.1 days of continuous rain are accepted, and 3.1 days of days with thunderstorms. The ideal temperature range is between 21 and 25 °C, thus lying 4–7 degrees lower than for beach tourism. Temperatures below 15 °C and above 30 °C are perceived as unacceptable. Statistically significant differences were found for several tourist types: Older tourists are more sensitive to heat, tourists with sports activities are more tolerant to cool temperatures, first-time visitors are more sensitive to rain and families with children prefer higher temperatures. From the results, some implications for mountain destinations arise: mountain destinations could be promoted as a heat refuge, and attracting sports tourists might be a promising way to reduce weather sensitivity; however, some variety of well-promoted weather independent attractions seems to be mandatory.

  3. 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.)

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. On the nature of rainfall in dry climate: Space-time patterns of convective rain cells over the Dead Sea region and their relations with synoptic state and flash flood generation

    Science.gov (United States)

    Belachsen, Idit; Marra, Francesco; Peleg, Nadav; Morin, Efrat

    2017-04-01

    -south negative gradient of mean annual rainfall in the study region was found to be negatively correlated with rain cells intensity and positively correlated with rain cells area. Additional analysis was done for convective rain cells over two nearby catchments located in the central part of the study region, by ascribing some of the rain events to observed flash-flood events. It was found that rain events associated with flash-floods have higher maximal rain cell intensity and lower minimal cell speed than rain events that did not lead to a flash-flood in the watersheds. This information contributes to our understanding of rain patterns over the dry area of the Dead Sea and their connection to flash-floods. The statistical distributions of rain cells properties can be used for high space-time resolution stochastic simulations of rain storms that can serve as an input to hydrological models.

  9. Diaspore bank of bryophytes in tropical rain forests: the importance of breeding system, phylum and microhabitat.

    Science.gov (United States)

    Maciel-Silva, Adaíses S; Válio, Ivany Ferraz Marques; Rydin, Håkan

    2012-02-01

    Diaspore banks are crucial for the maintenance and resilience of plant communities, but diaspore banks of bryophytes remain poorly known, especially from tropical ecosystems. This is the first study to focus on the role of diaspore banks of bryophytes in tropical rain forests. Our aim was to test whether microhabitat (substrate type) and species traits (breeding system, phylum) are important in explaining the diaspore bank composition. Using samples cultivated in the laboratory, we assessed the number of species and shoots emerging from bark, decaying wood and soil from two sites of the Atlantic rain forest (montane and sea level) in Brazil by comparing the contribution of species by phylum (mosses, liverworts) and breeding system (monoicous, dioicous). More species emerged from bark (68) and decaying wood (55) than from soil (22). Similar numbers of species were found at both sites. Mosses were more numerous in terms of number of species and shoots, and monoicous species dominated over dioicous species. Substrate pH had only weak effects on shoot emergence. Species commonly producing sporophytes and gemmae had a high contribution to the diaspore banks. These superficial diaspore banks represented the extant vegetation rather well, but held more monoicous species (probably short-lived species) compared to dioicous ones. We propose that diaspore bank dynamics are driven by species traits and microhabitat characteristics, and that short-term diaspore banks of bryophytes in tropical rain forests contribute to fast (re)establishment of species after disturbances and during succession, particularly dioicous mosses investing in asexual reproduction and monoicous mosses investing in sexual reproduction.

  10. 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...

  11. Dynamics of pollutant discharge in combined sewer systems during rain events: chance or determinism?

    Science.gov (United States)

    Hannouche, A; Chebbo, G; Joannis, C

    2014-01-01

    A large database of continuous flow and turbidity measurements cumulating data on hundreds of rain events and dry weather days from two sites in Paris (called Quais and Clichy) and one in Lyon (called Ecully) is presented. This database is used to characterize and compare the behaviour of the three sites at the inter-events scale. The analysis is probed through three various variables: total volumes and total suspended solids (TSS) masses and concentrations during both wet and dry weather periods in addition to the contributions of diverse-origin sources to event flow volume and TSS load values. The results obtained confirm the previous findings regarding the spatial consistency of TSS fluxes and concentrations between both sites in Paris having similar land uses. Moreover, masses and concentrations are proven to be correlated between Parisian sites in a way that implies the possibility of some deterministic processes being reproducible from one catchment to another for a particular rain event. The results also demonstrate the importance of the contribution of wastewater and sewer deposits to the total events' loads and show that such contributions are not specific to Paris sewer networks.

  12. 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...

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. [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.

  18. 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.

  19. 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.

  20. Impacts of simulated acid rain on recalcitrance of two different soils.

    Science.gov (United States)

    Dai, Zhongmin; Liu, Xingmei; Wu, Jianjun; Xu, Jianming

    2013-06-01

    Laboratory experiments were conducted to estimate the impacts of simulated acid rain (SAR) on recalcitrance in a Plinthudult and a Paleudalfs soil in south China, which were a variable and a permanent charge soil, respectively. Simulated acid rains were prepared at pH 2.0, 3.5, 5.0, and 6.0, by additions of different volumes of H2SO4 plus HNO3 at a ratio of 6 to 1. The leaching period was designed to represent 5 years of local annual rainfall (1,200 mm) with a 33 % surface runoff loss. Both soils underwent both acidification stages of (1) cation exchange and (2) mineral weathering at SAR pH 2.0, whereas only cation exchange occurred above SAR pH 3.5, i.e., weathering did not commence. The cation exchange stage was more easily changed into that of mineral weathering in the Plinthudult than in the Paleudalfs soil, and there were some K(+) and Mg(2+) ions released on the stages of mineral weathering in the Paleudalfs soil. During the leaching, the release of exchangeable base cations followed the order Ca(2+) >K(+) >Mg(2+) >Na(+) for the Plinthudult and Ca(2+) >Mg(2+) >Na(+) >K(+) for the Paleudalfs soil. The SARs above pH 3.5 did not decrease soil pH or pH buffering capacity, while the SAR at pH 2.0 decreased soil pH and the buffering capacity significantly. We conclude that acid rain, which always has a pH from 3.5 to 5.6, only makes a small contribution to the acidification of agricultural soils of south China in the short term of 5 years. Also, Paleudalfs soils are more resistant to acid rain than Plinthudult soils. The different abilities to prevent leaching by acid rain depend upon the parent materials, types of clay minerals, and soil development degrees.

  1. Seasonal variation of ozone deposition to a tropical rain forest in southwest Amazonia

    Directory of Open Access Journals (Sweden)

    U. Rummel

    2007-10-01

    Full Text Available Within the project EUropean Studies on Trace gases and Atmospheric CHemistry as a contribution to Large-scale Biosphere-atmosphere experiment in Amazonia (LBA-EUSTACH, we performed tower-based eddy covariance measurements of O3 flux above an Amazonian primary rain forest at the end of the wet and dry season. Ozone deposition revealed distinct seasonal differences in the magnitude and diel variation. In the wet season, the rain forest was an effective O3 sink with a mean daytime (midday maximum deposition velocity of 2.3 cm s−1, and a corresponding O3 flux of −11 nmol m−2 s−1. At the end of the dry season, the ozone mixing ratio was about four times higher (up to maximum values of 80 ppb than in the wet season, as a consequence of strong regional biomass burning activity. However, the typical maximum daytime deposition flux was very similar to the wet season. This results from a strong limitation of daytime O3 deposition due to reduced plant stomatal aperture as a response to large values of the specific humidity deficit. As a result, the average midday deposition velocity in the dry burning season was only 0.5 cm s−1. The large diel ozone variation caused large canopy storage effects that masked the true diel variation of ozone deposition mechanisms in the measured eddy covariance flux, and for which corrections had to be made. In general, stomatal aperture was sufficient to explain the largest part of daytime ozone deposition. However, during nighttime, chemical reaction with nitrogen monoxide (NO was found to contribute substantially to the O3 sink in the rain forest canopy. Further contributions were from non-stomatal plant uptake and other processes that could not be clearly identified.

    Measurements, made simultaneously on a 22 years old cattle pasture enabled the spatially and temporally direct comparison of O3

  2. A Synoptic Climatology of Heavy Rain Events in the Lake Eyre and Lake Frome Catchments

    Directory of Open Access Journals (Sweden)

    Michael John Pook

    2014-11-01

    Full Text Available The rare occasions when Lake Eyre in central, southern Australia fills with water excite great interest and produce major ecological responses. The filling of other smaller lakes such as Lake Frome, have less impact but can contribute important information about the current and past climates of these arid regions. Here, the dominant synoptic systems responsible for heavy rainfall over the catchments of Lake Eyre and Lake Frome since 1950 are identified and compared. Heavy rain events are defined as those where the mean catchment rainfall for 24 hours reaches a prescribed threshold. There were 25 such daily events at Lake Eyre and 28 in the Lake Frome catchment. The combination of a monsoon trough at mean sea level and a geopotential trough in the mid-troposphere was found to be the synoptic system responsible for the majority of the heavy rain events affecting Lake Eyre and one in five of the events at Lake Frome. Complex fronts where subtropical interactions occurred with Southern Ocean fronts also contributed over 20% of the heavy rainfall events in the Frome catchment. Surface troughs without upper air support were found to be associated with 10% or fewer of events in each catchment, indicating that mean sea level pressure analyses alone do not adequately capture the complexity of the heavy rainfall events. At least 80% of the heavy rain events across both catchments occurred when the Southern Oscillation Index (SOI was in its positive phase, and for Lake Frome, the SOI exceeded +10 on 60% of occasions, suggesting that the background atmospheric state in the Pacific Ocean was tilted towards La Niña. Hydrological modeling of the catchments suggests that the 12-month running mean of the soil moisture in a sub-surface layer provides a low frequency filter of the precipitation and matches measured lake levels relatively well.

  3. 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".

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Prediction of slant path rain attenuation statistics at various locations

    Science.gov (United States)

    Goldhirsh, J.

    1977-01-01

    The paper describes a method for predicting slant path attenuation statistics at arbitrary locations for variable frequencies and path elevation angles. The method involves the use of median reflectivity factor-height profiles measured with radar as well as the use of long-term point rain rate data and assumed or measured drop size distributions. The attenuation coefficient due to cloud liquid water in the presence of rain is also considered. Absolute probability fade distributions are compared for eight cases: Maryland (15 GHz), Texas (30 GHz), Slough, England (19 and 37 GHz), Fayetteville, North Carolina (13 and 18 GHz), and Cambridge, Massachusetts (13 and 18 GHz).

  10. Effects of acid rain and sulfur dioxide on marble dissolution

    Science.gov (United States)

    Schuster, Paul F.; Reddy, Michael M.; Sherwood, Susan I.

    1994-01-01

    Acid precipitation and the dry deposition of sulfur dioxide (SO2) accelerate damage to carbonate-stone monuments and building materials. This study identified and quantified environmental damage to a sample of Vermont marble during storms and their preceding dry periods. Results from field experiments indicated the deposition of SO2 gas to the stone surface during dry periods and a twofold increase in marble dissolution during coincident episodes of low rain rate and decreased rainfall pH. The study is widely applicable to the analysis of carbonate-stone damage at locations affected by acid rain and air pollution.

  11. 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

  12. 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...

  13. 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

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. Response of Methanogenic Microbial Communities to Desiccation Stress in Flooded and Rain-Fed Paddy Soil from Thailand

    Directory of Open Access Journals (Sweden)

    Andreas Reim

    2017-05-01

    Full Text Available Rice paddies in central Thailand are flooded either by irrigation (irrigated rice or by rain (rain-fed rice. The paddy soils and their microbial communities thus experience permanent or arbitrary submergence, respectively. Since methane production depends on anaerobic conditions, we hypothesized that structure and function of the methanogenic microbial communities are different in irrigated and rain-fed paddies and react differently upon desiccation stress. We determined rates and relative proportions of hydrogenotrophic and aceticlastic methanogenesis before and after short-term drying of soil samples from replicate fields. The methanogenic pathway was determined by analyzing concentrations and δ13C of organic carbon and of CH4 and CO2 produced in the presence and absence of methyl fluoride, an inhibitor of aceticlastic methanogenesis. We also determined the abundance (qPCR of genes and transcripts of bacterial 16S rRNA, archaeal 16S rRNA and methanogenic mcrA (coding for a subunit of the methyl coenzyme M reductase and the composition of these microbial communities by T-RFLP fingerprinting and/or Illumina deep sequencing. The abundances of genes and transcripts were similar in irrigated and rain-fed paddy soil. They also did not change much upon desiccation and rewetting, except the transcripts of mcrA, which increased by more than two orders of magnitude. In parallel, rates of CH4 production also increased, in rain-fed soil more than in irrigated soil. The contribution of hydrogenotrophic methanogenesis increased in rain-fed soil and became similar to that in irrigated soil. However, the relative microbial community composition on higher taxonomic levels was similar between irrigated and rain-fed soil. On the other hand, desiccation and subsequent anaerobic reincubation resulted in systematic changes in the composition of microbial communities for both Archaea and Bacteria. It is noteworthy that differences in the community composition were

  19. 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.

  20. Rainfall analysis for Indian monsoon region using the merged rain ...

    Indian Academy of Sciences (India)

    This daily analysis, being based on high dense rain gauge observations was found to be very ... monitoring and prediction of flood events to ini- .... First, station information (especially location) is verified. The precipitation values themselves are checked for coding or typing errors. The density of the spatial data used to ...

  1. Analysis of Historical Rainfall Data and Associated Risks on Rain ...

    African Journals Online (AJOL)

    distribution over the last six decades and tries to do a number of weather induced risk analysis in relation to different rainfall events that has special importance to the local farmers. Different type of rainfall events over the past six decades was assessed in relation to Ethiopian rain fed” tef” production. Tef is an important ...

  2. Intracranial calcification in Raine syndrome: radiological pathological correlation

    International Nuclear Information System (INIS)

    Al Mane, K.; Al-Dayel, F.; McDonald, P.

    1998-01-01

    We report the seventh known patient with Raine syndrome, a recently recognised, lethal sclerosing bone dysplasia associated with severe craniofacial dysmorphism and intracranial calcification in whom the CT findings are correlated with the gross and microscopic abnormalities found in the brain at autopsy. (orig.)

  3. Socio-Economic Impacts of Rain Water Harvesting Technologies in ...

    African Journals Online (AJOL)

    Technologies in Rwanda: A case study of Nyaruguru ... ownership and maintenance of established RWH technologies. ... production towards food security. .... The overall average family size for the households ..... respondents are aware of these techniques but few implement them- only 1 .... Water productivity in Rain-.

  4. Factorial study of rain garden design for nitrogen removal

    Science.gov (United States)

    Abstract Nitrate (〖NO〗_3^--N ) removal studies in bioretention systems showed great variability in removal rates and in some cases 〖NO〗_3^--N was exported. A 3-way factorial design (2 x 2 x 4) was devised for eight outdoor un-vegetated rain gardens to evaluate the effects of ...

  5. Rain-induced bistatic scattering at 60 GHz

    NARCIS (Netherlands)

    Zanden, van der H.T.; Watson, R.J.; Herben, M.H.A.J.

    2007-01-01

    This paper presents the results of a study into the modeling and prediction of rain-induced bistatic scattering at 60 GHz. The bistatic radar equation together withMie theory is applied as the basis for calculating the scattering. Together with the attenuation induced by the medium before and after

  6. 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.

  7. 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.

  8. Golden rain tree leaf extracts as potential inhibitor of lipid ...

    African Journals Online (AJOL)

    This study was designed to evaluate the peroxyl radical scavenging capacity and deoxyribonucleic acid (DNA) protective effect of extract/fractions of Koelreuteria paniculata Laxm. (Golden rain tree) in lipid peroxidation assay and calf thymus DNA protection assay. The leaves of the plant were extracted with different ...

  9. Rain-induced cross-polarization effects on satellite ...

    African Journals Online (AJOL)

    Rain-induced cross-polarization effects on satellite telecommunication in some tropical location. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, and ...

  10. Mechanics of Interrill Erosion with Wind-Driven Rain (WDR)

    Science.gov (United States)

    This article provides an evaluation analysis for the performance of the interrill component of the Water Erosion Prediction Project (WEPP) model for Wind-Driven Rain (WDR) events. The interrill delivery rates (Di) were collected in the wind tunnel rainfall simulator facility of the International Cen...

  11. 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

  12. Histochemical Characterization of Rain-Forest Strain of Onchocerca ...

    African Journals Online (AJOL)

    Abstract: The histochemical characterization of rain-forest strain of Onchocerca volvulus isolated in Akamkpa of Cross River State, Nigeria was studied. In a preliminary survey of 350 persons from eight villages, 75(21.4%) were found to be positive for the parasite. Males (23.6%) were more infected than the females but there ...

  13. 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.

  14. Characterization and morphology of solids suspended in rain water

    International Nuclear Information System (INIS)

    Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la

    2000-01-01

    This work presents the results obtained from the analysis of rain water in Mexico. The study treats over the characterization and morphology of the solids suspended in form of particles in the atmosphere. The solids suspended were obtained of the pluvial precipitations after these have been centrifuged. Subsequently of the separation, the particulate matter was analysed by Sem and X-ray dispersive energy

  15. Removal of plant nutrients from tree crowns by rain

    Energy Technology Data Exchange (ETDEWEB)

    Tamm, C O

    1951-01-01

    The composition of rain water samples collected beneath trees, as compared with samples from an open field, has been investigated during part of the autumn of 1950. Considerable amounts of calcium, potassium and sodium have been found in water collected beneath trees, together with smaller amounts of nitrogen and phosphorus.

  16. Disturbance, diversity and distributions in Central African rain forest

    NARCIS (Netherlands)

    Gemerden, van B.S.

    2004-01-01

    The aim of this study is to gain insight in the impact of human land use on plant community composition, diversity and levels of endemism in Central African rain forest. Human disturbance in this region is causing large-scale habitat degradation. The two most widespread forms of land use are

  17. Rain Tolk : "Jan Uuspõld on asendamatu" / Greta Kaupmees

    Index Scriptorium Estoniae

    Kaupmees, Greta

    2006-01-01

    Kanal 2 saate "TOP 10" naljameeste pingereas platseerus näitleja Jan Uuspõld 4. kohale. Teda iseloomustades pole üks komöödiafilmi "Jan Uuspõld läheb Tartusse" autoreid Rain Tolk kiitusega kitsi

  18. Quantification of Rain Induced Artifacts on Digital Satellite Television ...

    African Journals Online (AJOL)

    The presence of artifacts on the high definition television (TV) content and the eventual loss of the digital TV signals to rain is still a major concern to satellite operators, digital satellite television (DSTV) and terrestrial television content providers. In this paper, the artifacts present in a typical DSTV signal is examined on a ...

  19. Plant diversity after rain-forest fires in Borneo

    NARCIS (Netherlands)

    Eichhorn, Karl August Otto

    2006-01-01

    In the last two decades El-Niño-induced fires have caused widespread destruction of forests in East Kalimantan. The 1997-98 fires were the most extensive yet. The post-fire situation was studied in detail by field assessments and high-resolution SAR-images. My results show that rain forests are

  20. Growth and yield model application in tropical rain forest management

    Science.gov (United States)

    James Atta-Boateng; John W., Jr. Moser

    2000-01-01

    Analytical tools are needed to evaluate the impact of management policies on the sustainable use of rain forest. Optimal decisions concerning the level of management inputs require accurate predictions of output at all relevant input levels. Using growth data from 40 l-hectare permanent plots obtained from the semi-deciduous forest of Ghana, a system of 77 differential...

  1. Lessons Learnt on Rain Forest Management for Wood Production in ...

    African Journals Online (AJOL)

    The study was carried out with the aim of analyzing and establishing what lessons have been learnt from positive and negative experiences of various initiatives, projects and programmes aiming at sustainable management, use and conservation of rain forests in Sub-Saharan Africa. The lessons learnt from the case ...

  2. Estimating Effects Of Rain On Ground/Satellite Communication

    Science.gov (United States)

    Manning, R. M.

    1992-01-01

    LeRC-SLAM provides static and dynamic statistical assessment of impact of attenuation by rain on communication link established between Earth terminal and geosynchronous satellite. Program designed for use in specification, design, and assessment of satellite link for any terminal location in continental United States. IBM PC version written in Microsoft QuickBASIC, and Macintosh version written in Microsoft Basic.

  3. Fog and Rain Water Collection from Trees in the Dhofar Region in the Sultanate of Oman

    Directory of Open Access Journals (Sweden)

    S. A. Abdul-Wahab

    2009-06-01

    Full Text Available This work had two purposes. The first was to measure and investigate the amount of fog and rain water collected by a sample of trees during the summer monsoon season in the mountains of the Dhofar region in the south of Oman. The second purpose was to assess the potential of trees with different leaf shapes, sizes and cross sectional canopy areas to collect fog and rain water in the area. In order to meet these purposes three different tree species, were selected for experimental investigation and field measurements. They included fig, lemon, and tamarind trees. The experiments were designed and implemented in the monsoon season of 2006, between the 13th of July and the 3rd of September. The daily measurements of water collection showed that the three species of tree have different water collection capacities. It was found that the fig tree collected the least water. The fog water collection of the fig tree over a period of 47 days between the 13th of July and the 3rd of September was 140.5 L/m2, or an average of 2.7 L/m2/d. The fog water collection of the lemon tree was 243.0 L/m2, or an average of 4.4 L/m2/d. In terms of potential collection of the tamarind tree, the results showed that it collected a fog water of 218.9 L/m2, or an average of 4.3 L/m2/d over the same period. The study contributes to the knowledge of how different tree species collect fog and rain water, and concludes with a set of recommendations.

  4. Response of transpiration to rain pulses for two tree species in a semiarid plantation

    Science.gov (United States)

    Chen, Lixin; Zhang, Zhiqiang; Zeppel, Melanie; Liu, Caifeng; Guo, Junting; Zhu, Jinzhao; Zhang, Xuepei; Zhang, Jianjun; Zha, Tonggang

    2014-09-01

    Responses of transpiration ( E c) to rain pulses are presented for two semiarid tree species in a stand of Pinus tabulaeformis and Robinia pseudoacacia. Our objectives are to investigate (1) the environmental control over the stand transpiration after rainfall by analyzing the effect of vapor pressure deficit (VPD), soil water condition, and rainfall on the post-rainfall E c development and recovery rate, and (2) the species responses to rain pulses and implications on vegetation coverage under a changing rainfall regime. Results showed that the sensitivity of canopy conductance ( G c) to VPD varied under different incident radiation and soil water conditions, and the two species exhibited the same hydraulic control (-d G c/dlnVPD to G cref ratio) over transpiration. Strengthened physiological control and low sapwood area of the stand contributed to low E c. VPD after rainfall significantly influenced the magnitude and time series of post-rainfall stand E c. The fluctuation of post-rainfall VPD in comparison with the pre-rainfall influenced the E c recovery. Further, the stand E c was significantly related to monthly rainfall, but the recovery was independent of the rainfall event size. E c enhanced with cumulative soil moisture change (ΔVWC) within each dry-wet cycle, yet still was limited in large rainfall months. The two species had different response patterns of post-rainfall E c recovery. E c recovery of P. tabulaeformis was influenced by the pre- and post-rainfall VPD differences and the duration of rainless interval. R. pseudoacacia showed a larger immediate post-rainfall E c increase than P. tabulaeformis did. We, therefore, concluded that concentrated rainfall events do not trigger significant increase of transpiration unless large events penetrate the deep soil and the species differences of E c in response to pulses of rain may shape the composition of semiarid woodlands under future rainfall regimes.

  5. 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.

  6. 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.

  7. Attenuation of surface waves due to monsoon rains: A model study for the north Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.; Kumar, B.P.; Sarma, Y.V.B.

    The dynamic interaction of intense rain with waves based on momentum exchange is applied to a second generation wave model to predict wave attenuation during monsoon. The scheme takes into account the characteristics of rain and wave parameters...

  8. 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...

  9. 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...

  10. 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...

  11. Export of 134 Cs and 137 Cs in the Fukushima river systems at heavy rains by Typhoon Roke in September 2011

    Directory of Open Access Journals (Sweden)

    S. Nagao

    2013-10-01

    Full Text Available At stations on the Natsui River and the Same River in Fukushima Prefecture, Japan, effects of a heavy rain event on radiocesium export were studied after Typhoon Roke during 21–22 September 2011, six months after the Fukushima Dai-ichi Nuclear Power Plant accident. Radioactivity of 134Cs and 137Cs in river waters was 0.009–0.098 Bq L−1 in normal flow conditions during July–September 2011, but it increased to 0.85 Bq L−1 in high flow conditions because of heavy rains occurring with the typhoon. The particulate fractions of 134Cs and 137Cs were 21–56% of total radiocesium in the normal flow condition, but were close to 100% after the typhoon. These results indicate that the pulse input of radiocesium associated with suspended particles from land to coastal ocean occurred because of the heavy rain event. Export flux of 134Cs and 137Cs attributable to the heavy rain accounts for 30–50% of the annual radiocesium flux from inland to coastal ocean region in 2011. Results show that rain events are one factor contributing to the transport and dispersion of radiocesium in river watersheds and coastal marine environments.

  12. 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.

  13. 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

  14. 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 ...

  15. 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

  16. 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

  17. 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

  18. Radioactive fallout in air and rain: results for 1985 and 1986

    International Nuclear Information System (INIS)

    Cambray, R.S.; Playford, K.; Lewis, G.N.J.; Burton, P.J.

    1987-10-01

    Samples of atmospheric particulate and rainwater have been collected from the United Kingdom and elsewhere. Results are presented of analyses of these samples for various fission products and certain other radionuclides. The average concentrations of long-lived fission products in air and rain in the United Kingdom in 1985 were near to or below the limit of detection and lower than at any time since measurements began in 1953. The Chernobyl accident of 26 April 1986 produced a sharp increase in the concentrations of caesium-137 in air and rain in the northern hemisphere. Levels of Cs-137 in some parts of the United Kingdom were greater than any previously recorded. Plutonium concentrations in air and rainwater were a very small fraction of the NRPB's Generalised Derived Limit for members of the public. There was negligible contribution from the Chernobyl accident. Strontium-90 deposited in the United Kingdom in 1985 was below the limit of detection. The deposits in 1986 were generally about 2% of that from Cs-137. The estimated cumulative worldwide deposit of Cs-137 at the end of 1986 is about 10% greater than at the end of 1985. This increase is attributable to the Chernobyl accident. The gamma and beta-ray dose rates from fallout at Chilton are estimated from the observed deposition. (author)

  19. A New Infrared Desert Dust Index over French Guyana Rain forest: First results

    Science.gov (United States)

    Molinie, J.; Barnacin, E.; Henry, J. L.; Gobinddass, M. L.; Panechou-Pulcherie, K.; Feuillard, T.; Nagau, J.

    2017-12-01

    Recently a NASA researcher showed the role of desert dust contribution for the Amazonian rain forest. In another hand, desert dust impact population health when PM 10 level reached values around and upper the PM 10 threshold of the 50 µg m-3, established by the World Health Organization (WHO). Infrared Desert Dust Index (IDDI) developed by Legrand with Meteosat infrared images, allow the following of desert dust plumes over semi-arid land. In French Guiana the WHO threshold is currently overpass in measurements done by ORA air quality network, in the two main towns located close to the coast. For inland population, it is very difficult to have continuous dust measures due to the low infrastructure supplies. We need to develop a tools in order to follow the crossing of desert dust over the French Guyana rain forest, from the coast to inland villages. Following the IDDI concept and comparing with VIIRS AOT EDR result over the same area, a modified IDDI for Amazonian region (IDDI_A) has been proposed to identify the dusty pixels over the forest. Despite of high cloud presence, a good correlation between AOT EDR and IDDI_A was obtained. The IDDI_A calculation has been applied over French Guiana area for different PM 10 level at Cayenne, a town along the coast.

  20. 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)

  1. 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

  2. US energy and the impact of acid rain legislation

    International Nuclear Information System (INIS)

    Weisel, J.H.; Kelly, J.E.

    1991-01-01

    The 1990 Amendment to the US Clean Air Act aims to mitigate damage to the environment caused by acid rain. This study considers whether earlier US government policies to promote increased use of abundant indigenous coal resources will be aborted by the 1990 Amendment. It also examines whether benefits to the environment and public health resulting from the new law outweigh costs to the consumer. Emphasis is placed on evaluating the efficiency of marketable permits in achieving minimum cost to comply with emission standards set by the amendment. The authors restrict the study to the sections of Title IV (Acid Rain) which pertain specifically to SO 2 emissions from electric utilities. 15 refs., 5 figs., 7 tabs

  3. Activity of earthworm in Latosol under simulated acid rain stress.

    Science.gov (United States)

    Zhang, Jia-En; Yu, Jiayu; Ouyang, Ying

    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. Results showed that earthworms tended to escape from the soil and eventually died for the SAR at pH = 2.0 as a result of acid toxicity. The catalase activity in the earthworms decreased with the SAR pH levels, whereas the superoxide dismutases activity in the earthworms showed a fluctuate pattern: decreasing from pH 6.5 to 5.0 and increasing from pH 5.0 to 4.0. Results implied that the growth of earthworms was retarded at the SAR pH ≤ 3.0.

  4. Measurement of strontium 90 in the rain fall-out

    International Nuclear Information System (INIS)

    Suratman; Soedyartomo; Suhartono.

    1976-01-01

    The procedure of radioactivity measurement of strontium 90 in the rain fallout as well as the measurement of the fallout gross beta activity have been studied. In the preliminary study strontium 90 is separated from other cations especially fission products by fuming nitric acid, and radioactivity measurement is carried out in the form of strontium oxalate. Data of radioactivity measurement of strontium 90 and the gross beta activity in the fallout are given. (author)

  5. 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 ...

  6. Technologies options for acid-rain control. Book chapter

    International Nuclear Information System (INIS)

    Princiotta, F.T.

    1992-01-01

    The report discusses acid rain control options available to the electric utility industry. They include coal switching, flue gas desulfurization, and such emerging lower cost technologies as Limestone Injection Multistage Burners (LIMB) and Advanced Silicate (ADVACATE), both developed by EPA, selective use of gas to reduce nitrogen oxides (NOx) and sulfur dioxide (SO2) in coal-fired boilers, and the use of Integrated Coal Gasification Combined Cycle (IGCC) technology

  7. 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.

  8. Radar subpixel-scale rainfall variability and uncertainty: lessons learned from observations of a dense rain-gauge network

    Directory of Open Access Journals (Sweden)

    N. Peleg

    2013-06-01

    Full Text Available Runoff and flash flood generation are very sensitive to rainfall's spatial and temporal variability. The increasing use of radar and satellite data in hydrological applications, due to the sparse distribution of rain gauges over most catchments worldwide, requires furthering our knowledge of the uncertainties of these data. In 2011, a new super-dense network of rain gauges containing 14 stations, each with two side-by-side gauges, was installed within a 4 km2 study area near Kibbutz Galed in northern Israel. This network was established for a detailed exploration of the uncertainties and errors regarding rainfall variability within a common pixel size of data obtained from remote sensing systems for timescales of 1 min to daily. In this paper, we present the analysis of the first year's record collected from this network and from the Shacham weather radar, located 63 km from the study area. The gauge–rainfall spatial correlation and uncertainty were examined along with the estimated radar error. The nugget parameter of the inter-gauge rainfall correlations was high (0.92 on the 1 min scale and increased as the timescale increased. The variance reduction factor (VRF, representing the uncertainty from averaging a number of rain stations per pixel, ranged from 1.6% for the 1 min timescale to 0.07% for the daily scale. It was also found that at least three rain stations are needed to adequately represent the rainfall (VRF < 5% on a typical radar pixel scale. The difference between radar and rain gauge rainfall was mainly attributed to radar estimation errors, while the gauge sampling error contributed up to 20% to the total difference. The ratio of radar rainfall to gauge-areal-averaged rainfall, expressed by the error distribution scatter parameter, decreased from 5.27 dB for 3 min timescale to 3.21 dB for the daily scale. The analysis of the radar errors and uncertainties suggest that a temporal scale of at least 10 min should be used for

  9. 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.)

  10. Comparative Analysis of Nitrate Levels in Pensacola Area Rain Water

    Science.gov (United States)

    Jacobs, J.; Caffrey, J. M.; Maestre, A.; Landing, W. M.

    2017-12-01

    Nitrate is an important constituent of acid rain and often correlated with atmospheric NOx levels. This link between air and water quality was tested over a course of summer 2017 and compared to data from 2005-2012. Rain water samples collected from late May through early July of 2017 were tested for pH and nitrate concentrations. These months were among the stormiest on record for the Northwest Florida region with a total rainfall of 648 mm. The data analyzed from these rain events was compared to previous data to show the trends of nitrate and pH levels in the rainwater. Median pH for this study was 5.2, higher than the medians between 2015-2012 which ranged from 4.2 to 5.0, while nitrate concentrations for this study were 15.2 µM. This contrasts with a significant drop in nitrate concentrations from 41 µM in 2005 and 2006 to around 12 µM between 2007 and 2012. The drop between 2006-7 was suspected to be a result of implementation of NOx controls at Plant Crist coal fired power plant and other Clean Air Act requirements. These inputs of nitrate and H+ ions from rainwater can have a significant influence water quality throughout the region.

  11. 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.

  12. [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.

  13. 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.

  14. 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.

  15. Drop Size Distribution - Based Separation of Stratiform and Convective Rain

    Science.gov (United States)

    Thurai, Merhala; Gatlin, Patrick; Williams, Christopher

    2014-01-01

    For applications in hydrology and meteorology, it is often desirable to separate regions of stratiform and convective rain from meteorological radar observations, both from ground-based polarimetric radars and from space-based dual frequency radars. In a previous study by Bringi et al. (2009), dual frequency profiler and dual polarization radar (C-POL) observations in Darwin, Australia, had shown that stratiform and convective rain could be separated in the log10(Nw) versus Do domain, where Do is the mean volume diameter and Nw is the scaling parameter which is proportional to the ratio of water content to the mass weighted mean diameter. Note, Nw and Do are two of the main drop size distribution (DSD) parameters. In a later study, Thurai et al (2010) confirmed that both the dual-frequency profiler based stratiform-convective rain separation and the C-POL radar based separation were consistent with each other. In this paper, we test this separation method using DSD measurements from a ground based 2D video disdrometer (2DVD), along with simultaneous observations from a collocated, vertically-pointing, X-band profiling radar (XPR). The measurements were made in Huntsville, Alabama. One-minute DSDs from 2DVD are used as input to an appropriate gamma fitting procedure to determine Nw and Do. The fitted parameters - after averaging over 3-minutes - are plotted against each other and compared with a predefined separation line. An index is used to determine how far the points lie from the separation line (as described in Thurai et al. 2010). Negative index values indicate stratiform rain and positive index indicate convective rain, and, moreover, points which lie somewhat close to the separation line are considered 'mixed' or 'transition' type precipitation. The XPR observations are used to evaluate/test the 2DVD data-based classification. A 'bright-band' detection algorithm was used to classify each vertical reflectivity profile as either stratiform or convective

  16. 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.

  17. Rainwater propagation through snowpack during rain-on-snow sprinkling experiments under different snow conditions

    Directory of Open Access Journals (Sweden)

    R. Juras

    2017-09-01

    Full Text Available The mechanisms of rainwater propagation and runoff generation during rain-on-snow (ROS events are still insufficiently known. Understanding storage and transport of liquid water in natural snowpacks is crucial, especially for forecasting of natural hazards such as floods and wet snow avalanches. In this study, propagation of rainwater through snow was investigated by sprinkling experiments with deuterium-enriched water and applying an alternative hydrograph separation technique on samples collected from the snowpack runoff. This allowed us to quantify the contribution of rainwater, snowmelt and initial liquid water released from the snowpack. Four field experiments were carried out during winter 2015 in the vicinity of Davos, Switzerland. Blocks of natural snow were isolated from the surrounding snowpack to inhibit lateral exchange of water and were exposed to artificial rainfall using deuterium-enriched water. The experiments were composed of four 30 min periods of sprinkling, separated by three 30 min breaks. The snowpack runoff was continuously gauged and sampled periodically for the deuterium signature. At the onset of each experiment antecedent liquid water was first pushed out by the sprinkling water. Hydrographs showed four pronounced peaks corresponding to the four sprinkling bursts. The contribution of rainwater to snowpack runoff consistently increased over the course of the experiment but never exceeded 86 %. An experiment conducted on a non-ripe snowpack suggested the development of preferential flow paths that allowed rainwater to efficiently propagate through the snowpack limiting the time for mass exchange processes to take effect. In contrast, experiments conducted on ripe isothermal snowpack showed a slower response behaviour and resulted in a total runoff volume which consisted of less than 50 % of the rain input.

  18. [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.

  19. 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%).

  20. 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.

  1. 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.

  2. 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

  3. Determination of Sr-90 in rain water samples

    International Nuclear Information System (INIS)

    Lima, M.F.; Cunha, I.I.L.

    1988-01-01

    A work that aim is to establish radiochemical method for the determination of Sr-90 in rain water samples has been studied, as a step in an environmental monitoring program of radioactive elements. The analysis includes the preconcentration of strontium diluted in a large volume sample by precipitation of strontium as carbonate, separation of strontium from interfering elements (calcium, barium and rare earths), separation of strontium from ytrium, precipitation of purified strontium and ytrium respectively as carbonate and oxalate, and counting of Sr-90 and Y-90 activities in a low background anticoincidence beta counter. (author) [pt

  4. The US Acid Rain Program: design, performance, and assessment

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1998-01-01

    permit prices. Property rights to permits have been well-defined, strictly enforced, and sources have been allowed to trade freely without administrative approval of each trade. Ignoring source location in this way has kept transaction costs at a minimum. In conclusion, the policy design of the ARP......The US Acid Rain Program (ARP) from 1990 allows 1,000 major electric utilities all over the US to trade SO2 permits. Historical emission rights have been grandfathered and the target level is 50% SO2 reduction. Market performance has been successfull with much trade activity and unexpectedly low...

  5. Accelerated rain erosion of wind turbine blade coatings

    DEFF Research Database (Denmark)

    Zhang, Shizhong

    . There are four chapters in the thesis. In chapter 1, a literature survey provides background information to the field. Topics discussed are the global wind energy development, possible wind turbine constructions, blade structures and materials, blade coatings, and liquid erosion mechanisms. In chapter 2......During operation, the fast-moving blades of wind turbines are exposed to continuous impacts with rain droplets, hail, insects, or solid particles. This can lead to erosion of the blades, whereby the electrical efficiency is compromised and expensive repairs may be required. One possible solution...

  6. Rain Scattering and Co-ordinate Distance Calculation

    Directory of Open Access Journals (Sweden)

    M. Hajny

    1998-12-01

    Full Text Available Calculations of scattered field on the rain objects are based on using of Multiple MultiPole (MMP numerical method. Both bi-static scattering function and bi-static scattering cross section are calculated in the plane parallel to Earth surface. The co-ordination area was determined using the simple model of scattering volume [1]. Calculation for frequency 9.595 GHz and antenna elevation of 25° was done. Obtained results are compared with calculation in accordance to ITU-R recommendation.

  7. [Effects of Tillage on Soil Respiration and Root Respiration Under Rain-Fed Summer Corn Field].

    Science.gov (United States)

    Lu, Xing-li; Liao, Yun-cheng

    2015-06-01

    To explore the effects of different tillage systems on soil respiration and root respiration under rain-fed condition. Based on a short-term experiment, this paper investigated soil respiration in summer corn growth season under four tillage treatments including subsoiling tillage (ST), no tillage (NT), rotary tillage (RT) and moldboard plow tillage (CT). The contribution of root respiration using root exclusion method was also discussed. The results showed that soil respiration rate presented a single peak trend under four tillage methods during the summer corn growing season, and the maximum value was recorded at the heading stage. The trends of soil respiration were as follows: heading stage > flowering stage > grain filling stage > maturity stage > jointing stage > seedling stage. The trends of soil respiration under different tillage systems were as follows: CT > ST > RT > NT. There was a significant correlation between soil respiration rate and soil temperatures (P soil respiration using exponential function equation. However, there was no significant correlation between soil respiration rate and soil moisture. Root respiration accounted for 45.13%-56.86% of the proportion of soil respiratio n with the mean value 51.72% during the summer corn growing season under different tillage systems. Therefore, root exclusion method could be used to study the contribution of crop growth to carbon emission, to compare effects of different tillage systems on the contribution of root respiration provides the bases for selecting the measures to slow down the decomposition of soil carbon.

  8. Importance of Rain Evaporation and Continental Convection in the Tropical Water Cycle

    Science.gov (United States)

    Worden, John; Noone, David; Bowman, Kevin; Beer, R.; Eldering, A.; Fisher, B.; Gunson, M.; Goldman, Aaron; Kulawik, S. S.; Lampel, Michael; hide

    2007-01-01

    Atmospheric moisture cycling is an important aspect of the Earth's climate system, yet the processes determining atmospheric humidity are poorly understood. For example, direct evaporation of rain contributes significantly to the heat and moisture budgets of clouds, but few observations of these processes are available. Similarly, the relative contributions to atmospheric moisture over land from local evaporation and humidity from oceanic sources are uncertain. Lighter isotopes of water vapour preferentially evaporate whereas heavier isotopes preferentially condense and the isotopic composition of ocean water is known. Here we use this information combined with global measurements of the isotopic composition of tropospheric water vapour from the Tropospheric Emission Spectrometer (TES) aboard the Aura spacecraft, to investigate aspects of the atmospheric hydrological cycle that are not well constrained by observations of precipitation or atmospheric vapour content. Our measurements of the isotopic composition of water vapour near tropical clouds suggest that rainfall evaporation contributes significantly to lower troposphere humidity, with typically 20% and up to 50% of rainfall evaporating near convective clouds. Over the tropical continents the isotopic signature of tropospheric water vapour differs significantly from that of precipitation, suggesting that convection of vapour from both oceanic sources and evapotranspiration are the dominant moisture sources. Our measurements allow an assessment of the intensity of the present hydrological cycle and will help identify any future changes as they occur.

  9. 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.

  10. 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

  11. 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...

  12. 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...

  13. 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...

  14. 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.

  15. 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...

  16. Breakdown coefficients and scaling properties of rain fields

    Directory of Open Access Journals (Sweden)

    D. Harris

    1998-01-01

    Full Text Available The theory of scale similarity and breakdown coefficients is applied here to intermittent rainfall data consisting of time series and spatial rain fields. The probability distributions (pdf of the logarithm of the breakdown coefficients are the principal descriptor used. Rain fields are distinguished as being either multiscaling or multiaffine depending on whether the pdfs of breakdown coefficients are scale similar or scale dependent, respectively. Parameter  estimation techniques are developed which are applicable to both multiscaling and multiaffine fields. The scale parameter (width, σ, of the pdfs of the log-breakdown coefficients is a measure of the intermittency of a field. For multiaffine fields, this scale parameter is found to increase with scale in a power-law fashion consistent with a bounded-cascade picture of rainfall modelling. The resulting power-law exponent, H, is indicative of the smoothness of the field. Some details of breakdown coefficient analysis are addressed and a theoretical link between this analysis and moment scaling analysis is also presented. Breakdown coefficient properties of cascades are also investigated in the context of parameter estimation for modelling purposes.

  17. Temporal variations of isotopes in arid rain storms

    International Nuclear Information System (INIS)

    Adar, E.M.; Dodi, A.; Geyh, M.A.; Yair, A.

    1999-01-01

    The distribution of isotopes in rainfall has long been used to elaborate on hydrological systems. Both isotopic composition of stable isotopes (oxygen-18 and deuterium) and tritium content are used to illuminate on sources of groundwater recharge and as tracers upon which groundwater fluxes are assessed. As runoff is concerned, stable isotopes have been used to identify flow paths and the precise location of the rain storm which produced the floods. Analyses of stable isotopes in arid storms in the Negev desert revealed clear discrepancy between the spatial isotopic composition in floods versus the spatial and temporal isotopic composition in rainfall. In addition, simple water balance revealed that the entire flood volume is equivalent to a very small portion of the rain storm, suggesting that a specific flood is produced by a very short and intensive portion of the rainfall. Therefore, knowledge of the weighted isotopic average of a rainfall can not serve as an adequate input function for modeling of desert floods. Since in arid environment, floods are considered as major source of groundwater recharge it also can not be used as input function for modeling of groundwater systems. This paper summarizes detailed isotopic study of short segments (∼2 mm each) of desert rainstorms as sampled in the Negev desert, Israel

  18. Acid rain compliance: Coordination of state and federal regulation

    International Nuclear Information System (INIS)

    Nordhaus, R.R.

    1992-01-01

    The Clean Air Act (CAA) Amendments of 1990 impose new controls on emissions by electric utilities of the two major precursors of acid rain: sulfur dioxide (SO2) and oxides of nitrogen (NOx). Utilities, and the utility holding company systems and power pools of which they are members, will be subject to extensive and costly compliance obligations under the new statute. Most of these utilities, utility systems, and power pools are regulated by more than one utility regulatory authority. Some utilities are regulated by several states, some by a single state and by the Federal Energy Regulatory Commission (FERC), and some by multiple states, by the FERC, and by the Securities and Exchange Commission (SEC). Utility regulators will need to coordinate their policies for ratemaking and for reviewing acid rain compliance strategies if least cost solutions are to be implemented without imposing on ratepayers and utility shareholders the costs and risks of inconsistent regulatory determinations. This article outlines the scope of the coordination problem and addresses possible approaches that utility regulators may take to deal with this problem

  19. 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.

  20. Rain-shadow: An area harboring "Gray Ocean" clouds

    Science.gov (United States)

    Padmakumari, B.; Maheskumar, R. S.; Harikishan, G.; Morwal, S. B.; Kulkarni, J. R.

    2018-06-01

    The characteristics of monsoon convective clouds over the rain-shadow region of north peninsular India have been investigated using in situ aircraft cloud microphysical observations collected during Cloud Aerosol Interaction and Precipitation Enhancement EXperiment (CAIPEEX). The parameters considered for characterization are: liquid water content (LWC), cloud vertical motion (updraft, downdraft: w), cloud droplet number concentration (CDNC) and effective radius (Re). The results are based on 15 research flights which were conducted from the base station Hyderabad during summer monsoon season. The clouds studied were developing congestus. The clouds have low CDNC and low updraft values resembling the oceanic convective clouds. The super-saturation in clouds is found to be low (≤0.2%) due to low updrafts. The land surface behaves like ocean surface during monsoon as deduced from Bowen ratio. Microphysically the clouds showed oceanic characteristics. However, these clouds yield low rainfall due to their low efficiency (mean 14%). The cloud parameters showed a large variability; hence their characteristic values are reported in terms of median values. These values will serve the numerical models for rainfall simulations over the region and also will be useful as a scientific basis for cloud seeding operations to increase the rainfall efficiency. The study revealed that monsoon convective clouds over the rain-shadow region are of oceanic type over the gray land, and therefore we christen them as "Gray Ocean" clouds.

  1. Spatial characterization of acid rain stress in Canadian Shield Lakes

    Science.gov (United States)

    Tanis, Fred J.

    1987-01-01

    The acidification of lake waters from airborne pollution is of continental proportions both in North America and Europe. A major concern of the acid rain problem is the cumulative ecosystem damage to lakes and forest. The number of lakes affected in northeastern U.S. and on the Canadian Shield is though to be enormous. How seasonal changes in lake transparency are related to annual acidic load was examined. The relationship between variations in lake acidification and ecophysical units was also examined. The utility of Thematic Mapper based observations to measure seasonal changes in the optical transparency in acid lakes was investigated. The potential for this optical response is related to a number of local ecophysical factors with bedrock geology being, perhaps, the most important. Other factors include sulfate deposition, vegetative cover, and terrain drainage/relief. The area of southern Ontario contains a wide variety of geologies from the most acid rain sensitive granite quartzite types to the least sensitive limestone dolomite sediments. Annual sulfate deposition ranges from 1.0 to 4.0 grams/sq m.

  2. Bacterial diversity and composition during rain events with and without Saharan dust influence reaching a high mountain lake in the Alps.

    Science.gov (United States)

    Peter, Hannes; Hörtnagl, Paul; Reche, Isabel; Sommaruga, Ruben

    2014-12-01

    The diversity of airborne microorganisms that potentially reach aquatic ecosystems during rain events is poorly explored. Here, we used a culture-independent approach to characterize bacterial assemblages during rain events with and without Saharan dust influence arriving to a high mountain lake in the Austrian Alps. Bacterial assemblage composition differed significantly between samples with and without Saharan dust influence. Although alpha diversity indices were within the same range in both sample categories, rain events with Atlantic or continental origins were dominated by Betaproteobacteria, whereas those with Saharan dust intrusions were dominated by Gammaproteobacteria. The high diversity and evenness observed in all samples suggests that different sources of bacteria contributed to the airborne assemblage collected at the lake shore. During experiments with bacterial assemblages collected during rain events with Saharan dust influence, cell numbers rapidly increased in sterile lake water from initially ∼3 × 103 cell ml-1 to 3.6-11.1 x105 cells ml-1 within 4-5 days, and initially, rare taxa dominated at the end of the experiment. Our study documents the dispersal of viable bacteria associated to Saharan dust intrusions travelling northwards as far as 47° latitude.

  3. 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.

  4. Characterizing the phylogenetic tree community structure of a protected tropical rain forest area in Cameroon.

    Science.gov (United States)

    Manel, Stéphanie; Couvreur, Thomas L P; Munoz, François; Couteron, Pierre; Hardy, Olivier J; Sonké, Bonaventure

    2014-01-01

    Tropical rain forests, the richest terrestrial ecosystems in biodiversity on Earth are highly threatened by global changes. This paper aims to infer the mechanisms governing species tree assemblages by characterizing the phylogenetic structure of a tropical rain forest in a protected area of the Congo Basin, the Dja Faunal Reserve (Cameroon). We re-analyzed a dataset of 11538 individuals belonging to 372 taxa found along nine transects spanning five habitat types. We generated a dated phylogenetic tree including all sampled taxa to partition the phylogenetic diversity of the nine transects into alpha and beta components at the level of the transects and of the habitat types. The variation in phylogenetic composition among transects did not deviate from a random pattern at the scale of the Dja Faunal Reserve, probably due to a common history and weak environmental variation across the park. This lack of phylogenetic structure combined with an isolation-by-distance pattern of taxonomic diversity suggests that neutral dispersal limitation is a major driver of community assembly in the Dja. To assess any lack of sensitivity to the variation in habitat types, we restricted the analyses of transects to the terra firme primary forest and found results consistent with those of the whole dataset at the level of the transects. Additionally to previous analyses, we detected a weak but significant phylogenetic turnover among habitat types, suggesting that species sort in varying environments, even though it is not predominating on the overall phylogenetic structure. Finer analyses of clades indicated a signal of clustering for species from the Annonaceae family, while species from the Apocynaceae family indicated overdispersion. These results can contribute to the conservation of the park by improving our understanding of the processes dictating community assembly in these hyperdiverse but threatened regions of the world.

  5. Characterizing the Phylogenetic Tree Community Structure of a Protected Tropical Rain Forest Area in Cameroon

    Science.gov (United States)

    Munoz, François; Couteron, Pierre; Hardy, Olivier J.; Sonké, Bonaventure

    2014-01-01

    Tropical rain forests, the richest terrestrial ecosystems in biodiversity on Earth are highly threatened by global changes. This paper aims to infer the mechanisms governing species tree assemblages by characterizing the phylogenetic structure of a tropical rain forest in a protected area of the Congo Basin, the Dja Faunal Reserve (Cameroon). We re-analyzed a dataset of 11538 individuals belonging to 372 taxa found along nine transects spanning five habitat types. We generated a dated phylogenetic tree including all sampled taxa to partition the phylogenetic diversity of the nine transects into alpha and beta components at the level of the transects and of the habitat types. The variation in phylogenetic composition among transects did not deviate from a random pattern at the scale of the Dja Faunal Reserve, probably due to a common history and weak environmental variation across the park. This lack of phylogenetic structure combined with an isolation-by-distance pattern of taxonomic diversity suggests that neutral dispersal limitation is a major driver of community assembly in the Dja. To assess any lack of sensitivity to the variation in habitat types, we restricted the analyses of transects to the terra firme primary forest and found results consistent with those of the whole dataset at the level of the transects. Additionally to previous analyses, we detected a weak but significant phylogenetic turnover among habitat types, suggesting that species sort in varying environments, even though it is not predominating on the overall phylogenetic structure. Finer analyses of clades indicated a signal of clustering for species from the Annonaceae family, while species from the Apocynaceae family indicated overdispersion. These results can contribute to the conservation of the park by improving our understanding of the processes dictating community assembly in these hyperdiverse but threatened regions of the world. PMID:24936786

  6. [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.

  7. 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.

  8. Precipitation Regime Shift Enhanced the Rain Pulse Effect on Soil Respiration in a Semi-Arid Steppe

    Science.gov (United States)

    Yan, Liming; Chen, Shiping; Xia, Jianyang; Luo, Yiqi

    2014-01-01

    The effect of resource pulses, such as rainfall events, on soil respiration plays an important role in controlling grassland carbon balance, but how shifts in long-term precipitation regime regulate rain pulse effect on soil respiration is still unclear. We first quantified the influence of rainfall event on soil respiration based on a two-year (2006 and 2009) continuously measured soil respiration data set in a temperate steppe in northern China. In 2006 and 2009, soil carbon release induced by rainfall events contributed about 44.5% (83.3 g C m−2) and 39.6% (61.7 g C m−2) to the growing-season total soil respiration, respectively. The pulse effect of rainfall event on soil respiration can be accurately predicted by a water status index (WSI), which is the product of rainfall event size and the ratio between antecedent soil temperature to moisture at the depth of 10 cm (r 2 = 0.92, Psoil temperature/moisture ratio which is usually associated with longer dry spells. We then analyzed a long-term (1953–2009) precipitation record in the experimental area. We found both the extreme heavy rainfall events (>40 mm per event) and the long dry-spells (>5 days) during the growing seasons increased from 1953–2009. It suggests the shift in precipitation regime has increased the contribution of rain pulse effect to growing-season total soil respiration in this region. These findings highlight the importance of incorporating precipitation regime shift and its impacts on the rain pulse effect into the future predictions of grassland carbon cycle under climate change. PMID:25093573

  9. Contributions: SAGE

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Contributions: SAGE. Space Alternating Generalized Expectation (SAGE) Maximization algorithm provides an iterative approach to parameter estimation when direct maximization of the likelihood function may be infeasible. Complexity is less in those applications ...

  10. Various Contributions

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Various Contributions. Developed an Off –Diagonal MIMO Canceller to mitigate Upstream Crosstalk in VDSL. Developed a low complexity, Expectation Maximization based iterative Crosstalk cancellation. Developed an optimal way of computational complexity ...

  11. Original contributions

    African Journals Online (AJOL)

    hefere

    Original contributions ... Results suggest that there is a significant positive ... psychological abuse, including economic abuse, intimidation, harassment, stalking, damage ... or maintaining the structure and function of the African home (Alio et al., 2011; Jewkes,. Levin ... Revictimisation occurs due to emotional violence and.

  12. 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

  13. 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?

  14. 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 ...

  15. 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.

  16. 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.…

  17. Radioactivity in rain water and the air observed in Japan 1954-1955

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Y

    1955-01-01

    Radioactivity was detected in the rain in southern Japan beginning May 14, 1954, reaching a maximum of 1 c/1 on May 16 at Kyoto University. Trajectories indicate air came from Bikini via the Philippines and Formosa. Activity from May to Sep 1954, was always stronger on the Pacific side of Japan than on Japan sea side, maximum concentrated at the beginning of rain.

  18. 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

  19. 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 ...

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

    NARCIS (Netherlands)

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

    2017-01-01

    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

  1. 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.

  2. 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!

  3. 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 ...

  4. 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...

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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)

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. Short-term prediction of rain attenuation level and volatility in Earth-to-Satellite links at EHF band

    Directory of Open Access Journals (Sweden)

    L. de Montera

    2008-08-01

    Full Text Available This paper shows how nonlinear models originally developed in the finance field can be used to predict rain attenuation level and volatility in Earth-to-Satellite links operating at the Extremely High Frequencies band (EHF, 20–50 GHz. A common approach to solving this problem is to consider that the prediction error corresponds only to scintillations, whose variance is assumed to be constant. Nevertheless, this assumption does not seem to be realistic because of the heteroscedasticity of error time series: the variance of the prediction error is found to be time-varying and has to be modeled. Since rain attenuation time series behave similarly to certain stocks or foreign exchange rates, a switching ARIMA/GARCH model was implemented. The originality of this model is that not only the attenuation level, but also the error conditional distribution are predicted. It allows an accurate upper-bound of the future attenuation to be estimated in real time that minimizes the cost of Fade Mitigation Techniques (FMT and therefore enables the communication system to reach a high percentage of availability. The performance of the switching ARIMA/GARCH model was estimated using a measurement database of the Olympus satellite 20/30 GHz beacons and this model is shown to outperform significantly other existing models.

    The model also includes frequency scaling from the downlink frequency to the uplink frequency. The attenuation effects (gases, clouds and rain are first separated with a neural network and then scaled using specific scaling factors. As to the resulting uplink prediction error, the error contribution of the frequency scaling step is shown to be larger than that of the downlink prediction, indicating that further study should focus on improving the accuracy of the scaling factor.

  15. Short-term prediction of rain attenuation level and volatility in Earth-to-Satellite links at EHF band

    Science.gov (United States)

    de Montera, L.; Mallet, C.; Barthès, L.; Golé, P.

    2008-08-01

    This paper shows how nonlinear models originally developed in the finance field can be used to predict rain attenuation level and volatility in Earth-to-Satellite links operating at the Extremely High Frequencies band (EHF, 20 50 GHz). A common approach to solving this problem is to consider that the prediction error corresponds only to scintillations, whose variance is assumed to be constant. Nevertheless, this assumption does not seem to be realistic because of the heteroscedasticity of error time series: the variance of the prediction error is found to be time-varying and has to be modeled. Since rain attenuation time series behave similarly to certain stocks or foreign exchange rates, a switching ARIMA/GARCH model was implemented. The originality of this model is that not only the attenuation level, but also the error conditional distribution are predicted. It allows an accurate upper-bound of the future attenuation to be estimated in real time that minimizes the cost of Fade Mitigation Techniques (FMT) and therefore enables the communication system to reach a high percentage of availability. The performance of the switching ARIMA/GARCH model was estimated using a measurement database of the Olympus satellite 20/30 GHz beacons and this model is shown to outperform significantly other existing models. The model also includes frequency scaling from the downlink frequency to the uplink frequency. The attenuation effects (gases, clouds and rain) are first separated with a neural network and then scaled using specific scaling factors. As to the resulting uplink prediction error, the error contribution of the frequency scaling step is shown to be larger than that of the downlink prediction, indicating that further study should focus on improving the accuracy of the scaling factor.

  16. Fagaceae tree species allocate higher fraction of nitrogen to photosynthetic apparatus than Leguminosae in Jianfengling tropical montane rain forest, China.

    Science.gov (United States)

    Tang, Jingchao; Cheng, Ruimei; Shi, Zuomin; Xu, Gexi; Liu, Shirong; Centritto, Mauro

    2018-01-01

    Variation in photosynthetic-nitrogen use efficiency (PNUE) is generally affected by several factors such as leaf nitrogen allocation and leaf diffusional conductances to CO2, although it is still unclear which factors significantly affect PNUE in tropical montane rain forest trees. In this study, comparison of PNUE, photosynthetic capacity, leaf nitrogen allocation, and diffusional conductances to CO2 between five Fagaceae tree species and five Leguminosae tree species were analyzed in Jianfengling tropical montane rain forest, Hainan Island, China. The result showed that PNUE of Fagaceae was significantly higher than that of Leguminosae (+35.5%), attributed to lower leaf nitrogen content per area (Narea, -29.4%). The difference in nitrogen allocation was the main biochemical factor that influenced interspecific variation in PNUE of these tree species. Fagaceae species allocated a higher fraction of leaf nitrogen to the photosynthetic apparatus (PP, +43.8%), especially to Rubisco (PR, +50.0%) and bioenergetics (PB +33.3%) in comparison with Leguminosae species. Leaf mass per area (LMA) of Leguminosae species was lower than that of Fagaceae species (-15.4%). While there was no significant difference shown for mesophyll conductance (gm), Fagaceae tree species may have greater chloroplast to total leaf surface area ratios and that offset the action of thicker cell walls on gm. Furthermore, weak negative relationship between nitrogen allocation in cell walls and in Rubisco was found for Castanopsis hystrix, Cyclobalanopsis phanera and Cy. patelliformis, which might imply that nitrogen in the leaves was insufficient for both Rubisco and cell walls. In summary, our study concluded that higher PNUE might contribute to the dominance of most Fagaceae tree species in Jianfengling tropical montane rain forest.

  17. Fagaceae tree species allocate higher fraction of nitrogen to photosynthetic apparatus than Leguminosae in Jianfengling tropical montane rain forest, China

    Science.gov (United States)

    Cheng, Ruimei; Shi, Zuomin; Xu, Gexi; Liu, Shirong; Centritto, Mauro

    2018-01-01

    Variation in photosynthetic-nitrogen use efficiency (PNUE) is generally affected by several factors such as leaf nitrogen allocation and leaf diffusional conductances to CO2, although it is still unclear which factors significantly affect PNUE in tropical montane rain forest trees. In this study, comparison of PNUE, photosynthetic capacity, leaf nitrogen allocation, and diffusional conductances to CO2 between five Fagaceae tree species and five Leguminosae tree species were analyzed in Jianfengling tropical montane rain forest, Hainan Island, China. The result showed that PNUE of Fagaceae was significantly higher than that of Leguminosae (+35.5%), attributed to lower leaf nitrogen content per area (Narea, –29.4%). The difference in nitrogen allocation was the main biochemical factor that influenced interspecific variation in PNUE of these tree species. Fagaceae species allocated a higher fraction of leaf nitrogen to the photosynthetic apparatus (PP, +43.8%), especially to Rubisco (PR, +50.0%) and bioenergetics (PB +33.3%) in comparison with Leguminosae species. Leaf mass per area (LMA) of Leguminosae species was lower than that of Fagaceae species (-15.4%). While there was no significant difference shown for mesophyll conductance (gm), Fagaceae tree species may have greater chloroplast to total leaf surface area ratios and that offset the action of thicker cell walls on gm. Furthermore, weak negative relationship between nitrogen allocation in cell walls and in Rubisco was found for Castanopsis hystrix, Cyclobalanopsis phanera and Cy. patelliformis, which might imply that nitrogen in the leaves was insufficient for both Rubisco and cell walls. In summary, our study concluded that higher PNUE might contribute to the dominance of most Fagaceae tree species in Jianfengling tropical montane rain forest. PMID:29390007

  18. 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.

  19. Anthropogenic and volcanic emission impacts on SO2 dynamics and acid rain profiles. Numerical study using WRF-Chem in a high-resolution modeling

    Science.gov (United States)

    Vela, A. V.; González, C. M.; Ynoue, R.; Rojas, N. Y.; Aristizábal, B. H.; Wahl, M.

    2017-12-01

    Eulerian 3-D chemistry transport models (CTM) have been widely used for the study of air quality in urban environments, becoming an essential tool for studying the impacts and dynamics of gases and aerosols on air quality. However, their use in Colombia is scarce, especially in medium-sized cities, which are experimenting a fast urban growth, increasing the risk associated with possible air pollution episodes. In the densely populated medium-sized Andean city of Manizales, Colombia - a city located on the western slopes of the central range of the Andes (urban population 368000; 2150 m.a.s.l), there is an influence of the active Nevado del Ruiz volcano, located 28 km to the southwest. This natural source emits daily gas and particle fluxes, which could influence the atmospheric chemistry of the city and neighboring towns. Hence, the zone presents a unique combination of anthropogenic and volcanic sulfur gas emissions, which affects SO2 dynamics in the urban area, influencing also in the formation of acid rain phenomenon in the city. Therefore, studies analyzing the relative contribution of anthropogenic and volcanic emission could contribute with a deep understanding about causes and dynamics of both acid rain phenomenon and ambient SO2 levels in Manizales. This work aimed to analyze the influence of anthropogenic (on-road vehicular and industrial point-sources) and volcanic sulfur emissions in SO2 atmospheric chemistry dynamics, evaluating its possible effects on acid rain profiles. Ambient SO2 levels and day-night rain samples were measured and used to analyze results obtained from the application of the fully-coupled on-line WRF-Chem model. Two high-resolution simulations were performed during two dry and wet one-week periods in 2015. Analysis of SO2 dispersion patterns and comparison with SO2 observations in the urban area were performed for three different scenarios in which natural and anthropogenic emissions were simulated separately. Results suggest that

  20. 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.

  1. Retrieving latent heating vertical structure from cloud and precipitation Profiles—Part I: Warm rain processes

    International Nuclear Information System (INIS)

    Min, Qilong; Li, Rui; Wu, Xiaoqing; Fu, Yunfei

    2013-01-01

    An exploratory study on physical based latent heat (LH) retrieval algorithm is conducted by parameterizing the physical linkages of hydrometeor profiles of cloud and precipitation to the major processes related to the phase change of atmospheric water. Specifically, rain events are segregated into three rain types: warm, convective, and stratiform, based on their dynamical and thermodynamical characteristics. As the first of the series, only the warm rain LH algorithm is presented and evaluated here. The major microphysical processes of condensation and evaporation for warm rain are parameterized through traditional rain growth theory, with the aid of Cloud Resolving Model (CRM) simulations. The evaluation or the self-consistency tests indicate that the physical based retrievals capture the fundamental LH processes associated with the warm rain life cycle. There is no significant systematic bias in terms of convection strength, illustrated by the month-long CRM simulation as the mesoscale convective systems (MCSs) experience from initial, mature, to decay stages. The overall monthly-mean LH comparison showed that the total LH, as well as condensation heating and evaporation cooling components, agree with the CRM simulation. -- Highlights: ► An exploratory study on physics-based warm rain latent heat retrieval algorithm. ► Utilize the full information of the vertical structures of cloud and rainfall. ► Directly link water mass measurements to latent heat at instantaneous pixel level. ► Applicable at various stages of cloud system life cycle

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.)

  7. Productivity differences and food security: a metafrontier analysis of rain-fed maize farmers in MasAgro in Mexico

    Directory of Open Access Journals (Sweden)

    M. Laura Donnet

    2017-04-01

    Full Text Available Rain-fed maize production in Mexico includes approximately 6 million hectares which variation in productivity represents huge challenges to meeting the sustainable intensification goals of the Sustainable Modernization of Traditional Agriculture (MasAgro program. We use the information available from farmers participating in this program to investigate the differences in productivity and the effects of the promoted practices and technologies in seven defined rain-fed maize regions. We do this by applying metafrontier analysis to measure the technical efficiency and the technology gap. The results show a range of technical efficiency from 70 to 100%, which indicates the gains that can be achieved through improved management of the current inputs and practices of farmers in the program, and a range of the environment–technology gap between 32 and 82%, which indicates the limitations of the production environment which would require innovations in technologies and policies particularly adapted for the dry, the tropical and the more traditional regions. Furthermore, the results show that the use of hybrid seed and selling into maize markets have the largest impact in increasing maize yields in all regions. The difference between the MasAgro farmers and the average farmers in each region suggest that scaling the project will contribute to increasing maize production and Mexico’s food self-sufficiency.

  8. 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

  9. 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.

  10. Long-term Seedling Dynamics of Tree Species in a Subtropical Rain Forest, Taiwan

    Directory of Open Access Journals (Sweden)

    Chia-Hao Chang-Yang

    2013-03-01

    Full Text Available Knowledge of demographical rates at seedling stage is critical for understanding forest composition and dynamics. We monitored the seedling dynamics of tree species in a subtropical rain forest in Fushan, northern Taiwan (24°45’ N, 121°35’ E during an 8-yr period (2003–2010. There were great temporal fluctuations in the seedling density, which might be largely driven by the pulses of seedling recruitment. Interspecific variation in the seedling abundance, however, was not related to the reproductive adult abundance. Previous studies showed that frequent typhoon disturbances contributed to the high canopy openness and high understory light availability at Fushan, which might benefit tree regeneration. But our results do not support this idea. Most of the newly recruited seedlings died within six months and only grew 1.55 ± 0.20 cm per year, which might be suppressed by the dense understory vegetation. Our results suggested that the majority of tree species in Fushan were recruitment limited, which might have important consequences for species coexistence. High temporal variability in recruitment density and low growth rates of seedlings emphasize the importance of long-term studies to our understandings of forest dynamics.

  11. Efficient utilization of rain water in hill agriculture

    International Nuclear Information System (INIS)

    Singh, S.R.; Singh, S.S.; Khan, A.R.

    2002-05-01

    Hill areas generally receive rainfall of around or more than 1150 mm. More than 2500 mm rainfall is received in about 30.2 million ha hilly area of the country. Besides many other factors high rainfall and heavy runoff are mainly responsible for low productivity. Because of sloppy characters and shallow soil depth, major fraction of rainwater is lost as runoff. Invariably evaporation exceeds the moisture stored and thereby depletes soils of their moisture reserve when crops are to be sown. Too much water at one time and too little in another during the same year causes wide instability in the production and productivity (Gupta et al., 2000). In high rainfall/hilly areas small and scattered land holdings exclusively rain dependent subsistence type of agriculture, low irrigated area of eastern Himalaya (northeastern region of India) further aggravate the problem. Harvesting of runoff at micro level for storage and recycling, control of erosion and moisture conservation are necessary and possible measures for better crop production. (author)

  12. Vulnerability, survival and shame in Nina Raine's Tiger Country.

    Science.gov (United States)

    Bowman, Deborah

    2017-12-01

    Shame in healthcare remains relatively underexplored, yet it is commonplace and its impact is significant. This paper explores shame in healthcare using Nina Raine's 2011 play Tiger Country Three manifestations of shame are explored, namely (1) shame in relation to professional identity and survival in the clinical workplace; (2) shame and illness as experienced by both patients and doctors; and (3) the systemic and organisational influences on shame within healthcare systems. I suggest that the theatre is particularly well-placed to elucidate shame, and that Tiger Country demonstrates the prevalence and impact of shame on clinical work. Shame has a fundamental and overlooked relationship with damaging and well-documented phenomena in healthcare, including moral distress, ethical erosion, compassion fatigue, burnout, stress and ill health. Attention to shame is essential for those interested in medicine and healthcare and must, I propose, include the experiences and perceptions of those who provide care, as well as attending to those who receive care. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Report on the International Peer Review of RAINS-ASIA

    Energy Technology Data Exchange (ETDEWEB)

    Dovland, H. [ed.

    1995-10-01

    Many Asian countries have experienced rapid economic growth during recent years and this trend is expected to continue. The economic growth is accompanied by increasing energy demand, with coal as the dominant energy source. For the first time a model has been specifically developed and applied for integrated assessment of future SO{sub 2} emissions in Asia. The report deals with the RAINS-ASIA model developed in Norway offering an opportunity to assess sulphur deposition and ecosystem protection levels resulting from different energy pathways and different emission control strategies. The cost of various control strategies are also provided. During the project an impressive database has been collected for the region (23 countries, 94 subregions and 355 large point sources). This was made possible through dedicated work by the project team, in close collaboration with scientific and technical institutions in several Asian countries. A further development of the model may include strengthening and widening the collaboration with Asian institutions, assistance in establishing appropriate monitoring programmes, and inclusion of other air pollutants than SO{sub 2}

  14. Modelling of HVDC wall bushing flashover in nonuniform rain

    International Nuclear Information System (INIS)

    Rizk, F.A.M.; Kamel, S.I.

    1991-01-01

    This paper presents the first mathematical model to provide necessary and sufficient conditions for flashover of an HVDC wall bushing under nonuniform rain. The suggested mechanism is initiated by streamer bridging of the dry zone enhanced by nonuniform voltage distribution along the bushing and within the dry zone. Fast voltage collapse across the dry zone die to energy stored in the bushing stray capacitance to ground leads to impulsive stressing of the wet part of the bushing. The nonuniform distribution of the impulse stress and the process of streamer bridging, fast voltage collapse as well as subsequent recharging of the bushing capacitances can lead to continued discharge propagation and flashover of the complete bushing. The findings of the model have been satisfactorily compared with previous experiments and field observations and can, for the first time, account for the following aspects of the flashover mechanism: critical dry zone length, polarity effect, specific leakage path, wet layer conductance per unit leakage length as well as the DC system voltage

  15. Predicting Kenya Short Rains Using the Indian Ocean SST

    Science.gov (United States)

    Peng, X.; Albertson, J. D.; Steinschneider, S.

    2017-12-01

    The rainfall over the Eastern Africa is charaterized by the typical bimodal monsoon system. Literatures have shown that the monsoon system is closely connected with the large-scale atmospheric motion which is believed to be driven by sea surface temperature anomalies (SSTA). Therefore, we may make use of the predictability of SSTA in estimating future Easter Africa monsoon. In this study, we tried predict the Kenya short rains (Oct, Nov and Dec rainfall) based on the Indian Ocean SSTA. The Least Absolute Shrinkage and Selection Operator (LASSO) regression is used to avoid over-fitting issues. Models for different lead times are trained using a 28-year training set (2006-1979) and are tested using a 10-year test set (2007-2016). Satisfying prediciton skills are achieved at relatively long lead times (i.e., 8 and 10 months) in terms of correlation coefficient and sign accuracy. Unlike some of the previous work, the prediction models are obtained from a data-driven method. Limited predictors are selected for each model and can be used in understanding the underlying physical connection. Still, further investigation is needed since the sampling variability issue cannot be excluded due to the limited sample size.

  16. 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

  17. 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)

  18. 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

  19. Projected changes to rain-on-snow events over North America

    Science.gov (United States)

    Jeong, Dae Il; Sushama, Laxmi

    2016-04-01

    Rain-on-snow (ROS) events have significant impacts on cold region ecosystems and water-related natural hazards, and therefore it is very important to assess how this hydro-meteorological phenomenon will evolve in a changing climate. This study evaluates the changes in ROS characteristics (i.e., frequency, amounts, and runoff) for the future 2041-2070 period with respect to the current 1976-2005 period over North America using six simulations, based on two Canadian RCMs, driven by two driving GCMs for RCP4.5 and 8.5 emission pathways. Projected changes to extreme runoff caused by the changes of the ROS characteristics are also evaluated. All simulations suggest general increases in ROS days in late autumn, winter, and early spring periods for most Canadian regions and northwestern USA for the future period, due to an increase in rain days in a warmer climate. Increases in the future ROS amounts are projected mainly due to an increase in ROS days, although increases in precipitation intensity also contributes to the future increases. Future ROS runoff is expected to increase more than future ROS amounts during snowmelt months as ROS events usually enhance runoff, given the land state and asociated reduced soil infiltration rate and also due to the faster snowmelt rate occuring during these events. The simulations also show that ROS events usually lead to extreme runoff over most of Canada and north-western and -central USA in the January-May snowmelt months for the current period and these show no significant changes in the future climate. However, the future ROS to total runoff ratio will significantly decrease for western and eastern Canada as well as north-western USA for these months, due to an overall increase of the fraction of direct snowmelt and rainfall generated runoff in a warmer climate. These results indicate the difficulties of flood risk and water resource managements in the future, particularly in Canada and north-western and -central USA, requiring

  20. Paleoecological Calibration In Central Guatemala: Modern Pollen Rain From Bryophyte Polsters And Surface Sediments

    Science.gov (United States)

    Finkelstein, S. A.; Avendano, C. E.; Cowling, S. A.

    2009-05-01

    Paleoecology requires understanding the correspondences between modern pollen rain and local-regional vegetation, in order to develop accurate paleovegetation reconstructions. Paleoecology in Guatemala has been developed largely over decades in the northern lowlands in close relationship with Classic Maya archaeology, where paleoenvironmental reconstructions have been made mainly through the use of fossil pollen. Scarcity of calibration studies in the Mesoamerican region however remains evident; nevertheless, they are necessary to produce reliable reconstructions. We present calibration pollen data from two locations in Central Guatemala: Lachua Lowlands and Purulha Highlands. Pollen spectra were analyzed from surface sediments samples (SS) from a lake and a small pond in Lachua, a river floodplain and a lake shore in Purulha. Bryophyte polsters samples (BP) were collected from the interior of minimally disturbed forests in both Lachua (rain forest) and Purulha (cloud forest). Pollen spectra between SS and BP differed in both locations. Analysis per location indicates that SS were more similar for Purulha, as compared to Lachua. Combined analysis of locations indicates that SS from both locations were related to anemophilous taxa - great production of pollen quantities that has high dispersion capacities-. This provides evidence that the pollen signal from SS is probably more regional than local. BP from Lachua and Purulha differed notably in their pollen signal, each location containing local taxa, tropical and temperate respectively. Some temperate anemophilous taxa were better represented in Lachua than in Purulha. Purulha SS were similar, and contained more taxa related to disturbance and anemophilous taxa. The arboreal pollen (AP) to non-arboreal (NAP) ratio (AP/NAP) of both SS and BP corresponded with the tree- prevalent landscape in Lachua. The SS AP/NAP ratio represented the deforested landscape of the river floodplain and lake environments in Purulha

  1. 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

  2. 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.

  3. 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.

  4. Spatial distribution and interspecific associations of tree species in a tropical seasonal rain forest of China.

    Directory of Open Access Journals (Sweden)

    Guoyu Lan

    Full Text Available Studying the spatial pattern and interspecific associations of plant species may provide valuable insights into processes and mechanisms that maintain species coexistence. Point pattern analysis was used to analyze the spatial distribution patterns of twenty dominant tree species, their interspecific spatial associations and changes across life stages in a 20-ha permanent plot of seasonal tropical rainforest in Xishuangbanna, China, to test mechanisms maintaining species coexistence. Torus-translation tests were used to quantify positive or negative associations of the species to topographic habitats. The results showed: (1 fourteen of the twenty tree species were negatively (or positively associated with one or two of the topographic variables, which evidences that the niche contributes to the spatial pattern of these species. (2 Most saplings of the study species showed a significantly clumped distribution at small scales (0-10 m which was lost at larger scales (10-30 m. (3 The degree of spatial clumping deceases from saplings, to poles, to adults indicates that density-dependent mortality of the offspring is ubiquitous in species. (4 It is notable that a high number of positive small-scale interactions were found among the twenty species. For saplings, 42.6% of all combinations of species pairs showed positive associations at neighborhood scales up to five meters, but only 38.4% were negative. For poles and adults, positive associations at these distances still made up 45.5% and 29.5%, respectively. In conclusion, there is considerable evidence for the presence of positive interactions among the tree species, which suggests that species herd protection may occur in our plot. In addition, niche assembly and limited dispersal (likely contribute to the spatial patterns of tree species in the tropical seasonal rain forest in Xishuangbanna, China.

  5. 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.

  6. 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.

  7. On the discrepancies between theoretical and measured below-cloud particle scavenging coefficients for rain – a numerical investigation using a detailed one-dimensional cloud microphysics model

    Directory of Open Access Journals (Sweden)

    X. Wang

    2011-11-01

    Full Text Available Existing theoretical formulations for the size-resolved scavenging coefficient Λ(d for atmospheric aerosol particles scavenged by rain predict values lower by one to two orders of magnitude than those estimated from field measurements of particle-concentration changes for particles smaller than 3 μm in diameter. Vertical turbulence is not accounted for in the theoretical formulations of Λ(d but does contribute to the field-derived estimates of Λ(d due to its influence on the overall concentration changes of aerosol particles in the layers undergoing impaction scavenging. A detailed one-dimensional cloud microphysics model has been used to simulate rain production and below-cloud particle scavenging, and to quantify the contribution of turbulent diffusion to the overall Λ(d values calculated from particle concentration changes. The relative contribution of vertical diffusion to below-cloud scavenging is found to be largest for submicron particles under weak precipitation conditions. The discrepancies between theoretical and field-derived Λ(d values can largely be explained by the contribution of vertical diffusion to below-cloud particle scavenging for all particles larger than 0.01 μm in diameter for which field data are available. The results presented here suggest that the current theoretical framework for Λ(d can provide a reasonable approximation of below-cloud aerosol particle scavenging by rain in size-resolved aerosol transport models if vertical diffusion is also considered by the models.

  8. GPM GROUND VALIDATION ENVIRONMENT CANADA (EC) MICRO RAIN RADAR (MRR) GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — Environment Canada (EC) collected data from the Micro Rain Radar (MRR) during the GPM Cold-season Precipitation Experiment (GCPEx) in Ontario, Canada during the...

  9. GPM GROUND VALIDATION ADVANCED MICROWAVE RADIOMETER RAIN IDENTIFICATION (ADMIRARI) GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Advanced Microwave Radiometer Rain Identification (ADMIRARI) GCPEx dataset measures brightness temperature at three frequencies (10.7, 21.0...

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

    African Journals Online (AJOL)

    Choice-Academy

    Ethiopian Journal of Environmental Studies and Management Vol.1 No.2 June. 2008 ... an urgent attention for improving productivity ..... difference between rain fed and supplementary irrigation in all plots examined across time interval. 0. 5.

  11. Rain use efficiency across a precipitation gradient on the Tibetan Plateau

    Science.gov (United States)

    Rain use efficiency (RUE), commonly described as the ratio of aboveground net primary production (ANPP) to mean annual precipitation (MAP), is a critical indicator for predicting potential responses of grassland ecosystems to changing precipitation regimes. However, current understanding on patterns...

  12. On the Use of a 77 GHz Automotive Radar as a Microwave Rain Gauge

    Directory of Open Access Journals (Sweden)

    S. Bertoldo

    2018-02-01

    Full Text Available The European Telecommunications Standards Institute (ETSI defines the frequency band of 77 GHz (W-band as the one dedicated to automatic cruise control long-range radars. A car can be thought as a moving integrated weather sensor since it can provide meteorological information exploiting the sensors installed on board. This work presents the preliminary analysis of how a 77 GHz mini radar can be used as a short range microwave rain gauge. After the discussion of the Mie scattering formulation applied to a microwave rain gauge working in the W-band, the proposal of a new Z-R equation to be used for correct rain estimation is given. Atmospheric attenuation and absorption are estimated taking into account the ITU-T recommendations. Functional requirements in adapting automatic cruise control long-range radar to a microwave rain gauge are analyzed. The technical specifications are determined in order to meet the functional requirements.

  13. Effect of Rain Acidity Upon Mobility of Cs-134 and Co-60 in Soil

    International Nuclear Information System (INIS)

    Ruangchuay, S.; Harvey, N.W.; Sriyotha, P.

    1998-01-01

    This research was aimed to study the effects of groundwater and acid rain upon the mobility of radionuclides (Cs-134 and Co-60) in contaminated top soil. Clay soil was homogeneously packed in columns with dimension φ.12.5 cm. * 50 cm.. At the top 5 cm. of the columns, soil contaminated with radionuclides was added with the same consistency. Column were kept standing for 4 months in an artificial water table kept at 3 cm. from the bottom. During this period artificial acid rain with pH3, 4.5 and 6 was applied weekly at the top. Soil samples were taken every 30 days for examination of total and extracable radioactivity. It was shown that with the aide of the rain radionuclide movement down the profile was greater, with Co-60 > Cs-134. However acidity of the rain shown no effect on their movement

  14. 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)

  15. 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

  16. The effect of daytime rain on the Indian Flying Fox (Mammalia: Chiroptera: Pteropodidae Pteropus giganteus

    Directory of Open Access Journals (Sweden)

    S. Baskaran

    2016-02-01

    Full Text Available Excessive water loss during the day due to heat stress in bats of the genus Pteropus appears to be inevitable, because these bats are exposed to direct sunlight.  Rain also affects the rest pattern of the Indian Flying Fox Pteropus giganteus during the day.  When rain occurred during the day, most of the bats hung in a slanting position and did not exhibit any movements.  After rain, they licked both ventral and dorsal surfaces of the wing membrane and scratched their body with their thumb claws.  They also licked the water droplets that remained on the leaves and branches of the tree.  Even though their rest had been affected by the rain the bats utilized the water droplets to quench their thirst, cool their body and clean their fur.  The construction of water reservoirs near Pteropus roosts will help to assure their long-term conservation. 

  17. Research note on investigation on the poor performance of rain fed ...

    African Journals Online (AJOL)

    Tanzania Journal of Agricultural Sciences ... Rainfall (R) and Reference crop evapotranspiration (ETo) data were ... Findings indicate that, long rains are marked by a period of moisture sufficiency (R> ETo) lasting 60 days beginning March ...

  18. 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...

  19. Gastrointestinal symptoms among swimmers following rain events at a beach impacted by urban runoff

    Science.gov (United States)

    Gastrointestinal symptoms among swimmers following rain events at a beach impacted by urban runoff Timothy J. Wade, Reagan R. Converse, Elizabeth A. Sams, Ann H. Williams, Edward Hudgens, Alfred P. Dufour Gastrointestinal symptoms among swimmers have been associated with fecal ...

  20. The effect of acid rain stress on chlorophyll, peroxidase of the conservation of rare earth elements

    International Nuclear Information System (INIS)

    Chongling, Y.; Yetang, H.; Xianke, Y.; Shunzhen, F.; Shanql, W.

    1998-01-01

    Full text: Based on pot experiment, the effect of acid rain stress on chlorophyll, peroxidase of wheat, the relationship of them and the conservation of rare earth elements has been studied. The result showed: stress of acid rain resulted in decrease of chlorophyll content and a/b values, chlorophyll a/b value and chlorophyll content is positive correlation with pH value of acid rain: peroxidase activity was gradually rise with pH value decrease, which indirectly increased decomposition intensity of chlorophyll. Decreased content and a/b value of chlorophyll further speeded blade decay affected the transport and transformation of light energy and metabolism of carbohydrates. After being treated by rare earth elements content and pH value of chlorophyll and peroxidase activity could be relatively stable. Therefore, under lower acidity condition, rare earth elements can influence the effect of acid rain on chlorophyll and peroxidase activity of wheat

  1. Implications of Warm Rain in Shallow Cumulus and Congestus Clouds for Large-Scale Circulations

    Science.gov (United States)

    Nuijens, Louise; Emanuel, Kerry; Masunaga, Hirohiko; L'Ecuyer, Tristan

    2017-11-01

    Space-borne observations reveal that 20-40% of marine convective clouds below the freezing level produce rain. In this paper we speculate what the prevalence of warm rain might imply for convection and large-scale circulations over tropical oceans. We present results using a two-column radiative-convective model of hydrostatic, nonlinear flow on a non-rotating sphere, with parameterized convection and radiation, and review ongoing efforts in high-resolution modeling and observations of warm rain. The model experiments investigate the response of convection and circulation to sea surface temperature (SST) gradients between the columns and to changes in a parameter that controls the conversion of cloud condensate to rain. Convection over the cold ocean collapses to a shallow mode with tops near 850 hPa, but a congestus mode with tops near 600 hPa can develop at small SST differences when warm rain formation is more efficient. Here, interactive radiation and the response of the circulation are crucial: along with congestus a deeper moist layer develops, which leads to less low-level radiative cooling, a smaller buoyancy gradient between the columns, and therefore a weaker circulation and less subsidence over the cold ocean. The congestus mode is accompanied with more surface precipitation in the subsiding column and less surface precipitation in the deep convecting column. For the shallow mode over colder oceans, circulations also weaken with more efficient warm rain formation, but only marginally. Here, more warm rain reduces convective tops and the boundary layer depth—similar to Large-Eddy Simulation (LES) studies—which reduces the integrated buoyancy gradient. Elucidating the impact of warm rain can benefit from large-domain high-resolution simulations and observations. Parameterizations of warm rain may be constrained through collocated cloud and rain profiling from ground, and concurrent changes in convection and rain in subsiding and convecting branches of

  2. 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

  3. Effects of simulated acid rain on soil respiration and its components in a subtropical mixed conifer and broadleaf forest in southern China.

    Science.gov (United States)

    Liang, Guohua; Hui, Dafeng; Wu, Xiaoying; Wu, Jianping; Liu, Juxiu; Zhou, Guoyi; Zhang, Deqiang

    2016-02-01

    Soil respiration is a major pathway in the global carbon cycle and its response to environmental changes is an increasing concern. Here we explored how total soil respiration (RT) and its components respond to elevated acid rain in a mixed conifer and broadleaf forest, one of the major forest types in southern China. RT was measured twice a month in the first year under four treatment levels of simulated acid rain (SAR: CK, the local lake water, pH 4.7; T1, water pH 4.0; T2, water pH 3.25; and T3, water pH 2.5), and in the second year, RT, litter-free soil respiration (RS), and litter respiration (RL) were measured simultaneously. The results indicated that the mean rate of RT was 2.84 ± 0.20 μmol CO2 m(-2) s(-1) in the CK plots, and RS and RL contributed 60.7% and 39.3% to RT, respectively. SAR marginally reduced (P = 0.08) RT in the first year, but significantly reduced RT and its two components in the second year (P rain, the decline trend of RT in the forests in southern China appears to be attributable to the decline of soil respiration in the litter layer.

  4. Quantification of rain gauge measurement undercatch and wind speed correction

    Science.gov (United States)

    Pollock, Michael; Quinn, Paul; Dutton, Mark; Wilkinson, Mark

    2014-05-01

    Hydrological processes are adversely affected by systematic rain gauge inaccuracy due to wind induced undercatching. The implications of this are discussed and addressed. Despite evidence of the undercatch problem being cited in the past and the difficulty in solving such a complex problem; it has become an inconvenient truth to hydrologists that major inaccuracies in rainfall measurement exist. A two year long experiment using new equipment and improved data logging and telemetery techniques enriches this formative work to redress the wilful neglect with which accurate rainfall measurement has been treated in recent decades. Results from this work suggest that the annual systematic undercatch can be in the order of 20 percent in the UK. During specific periods (measured at high temporal resolution), this can rise to as high as 50 percent for a single wind impacted event. As one organisation, responsible for the environment in the UK, moves towards using fewer instruments (15 percent fewer in the next year), it is scarcely possible to overstate the importance in solving this problem. It had been hoped that new equipment, such as acoustic distrometer and weighing gauge technologies, would be able to reduce the magnitude of the bias. However, through data gathered in the 2 year experiment and through secondary sources from the 1970s and 1980s, it is demonstrated that this is not the case and that the same problems with undercatching remain now as they did then. We further postulate that wider, denser networks of inexpensive telemetered equipment are now possible but they must still address the undercatch issue. There is little merit in pointing out an age old problem if no solution is put forward to fix it. The aforementioned experiment has furnished new ideas and further work has been commissioned to address this problem. This will be achieved via the medium of a Knowledge Transfer Partnership between Newcastle University and an innovative equipment manufacturer

  5. Using the acid rain advisor to evaluate compliance strategies

    International Nuclear Information System (INIS)

    Stallard, G.S.; Anderson, A.A.

    1991-01-01

    Unlike prior Clean Air Act (CAA) legislation, the most recent amendments will require utilities to reduce SO 2 and NO x emissions for existing operating power station and provides for compliance strategies in which emissions for existing operating power stations and provides for compliance strategies in which emission reductions can be transferred from one unit to another. The Electric Power Research Institute (EPRI), in conjunction with the Department of Energy (DOE), is funding the development of the Coal Quality Expert (CQE), a comprehensive analytical/planning tool to consider the myriad of potential coal purchase decisions now facing the utility, including fuel switching, blending, coal beneficiation, and the installation of retrofit emission controls. The CQE will be built on the foundation of proven, validated computer models to the maximum extent possible, including EPRI's Coal Quality Impact Model (CQIM), a state-of-the-art computer model designed to evaluate cost/performance impacts of fuel switching at existing power plants. In addition, as the CQE development permits, interim computer products will be offered. The first of these products is the Acid Rain Advisor (ARA). The ARA complements the CQIM by providing the ability to rapidly evaluate the system-wide cost and reduction benefits which result from selecting various reduction techniques on various units within the system. Thus, with the ARA, the utility can efficiently combine cost/performance information, view overall system results, and rapidly consider various 'What if' alternatives to ensure that individual unit reduction strategies are consistent with the goals of the utility as a whole. This paper demonstrates the capabilities of the ARA, and by use of a 'sample analysis,' illustrates how a utility might develop and evaluate alternative CAA compliance strategies

  6. Odd man out : why are there fewer plant species in African rain forests ?

    OpenAIRE

    Couvreur, Thomas

    2015-01-01

    Although tropical rain forests represent the most species-rich terrestrial ecosystem on the planet, the three main rain forest regions (Neotropics, South-East Asia and continental Africa) are not equally diverse. Africa has been labeled the "odd man out" because of its perceived lower species diversity when compared to the Neotropics or South-East Asia. Understanding why, within a biome, certain regions have higher or lower species diversity provides important insights into the evolution of b...

  7. 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...

  8. Influence of rain water leakage on the hygrothermal performance of exterior insulation systems

    OpenAIRE

    Künzel, H.M.; Zirkelbach, D.

    2008-01-01

    This investigation shows that ETICS on light weight structures pose no moisture problem in cold and moderate climates when the detailing of joints and openings is well done, i.e. there is no rain water leakage. This holds for all locations investigated. However, if water leakage cannot be excluded completely and therefore the North-American Standard assumptions - penetration of 1% of the driving rain load - are applied this picture changes, making the drying potential an essential feature. Th...

  9. Speciation distribution and mass balance of copper and zinc in urban rain, sediments, and road runoff.

    Science.gov (United States)

    Zuo, Xiaojun; Fu, Dafang; Li, He

    2012-11-01

    Heavy metal pollution in road runoff had caused widespread concern since the last century. However, there are little references on metal speciation in multiple environmental media (e.g., rain, road sediments, and road runoff). Our research targeted the investigation of metal speciation in rain, road sediments, and runoff; the analysis of speciation variation and mass balance of metals among rain, road sediments, and runoff; the selection of main factors by principal component analysis (PCA); and the establishment of equation to evaluate the impact of rain and road sediments to metals in road runoff. Sequential extraction procedure contains five steps for the chemical fractionation of metals. Flame atomic absorption spectrometry (Shimadzu, AA-6800) was used to determine metal speciation concentration, as well as the total and dissolved fractions. The dissolved fractions for both Cu and Zn were dominant in rain. The speciation distribution of Zn was different from that of Cu in road sediments, while speciation distribution of Zn is similar to that of Cu in runoff. The bound to carbonates for both Cu and Zn in road sediments were prone to be dissolved by rain. The levels of Cu and Zn in runoff were not obviously influenced by rain, but significantly influenced by road sediments. The masses for both Cu and Zn among rain, road sediments, and road runoff approximately meet the mass balance equation for all rainfall patterns. Five principal factors were selected for metal regression equation based on PCA, including rainfall, average rainfall intensity, antecedent dry periods, total suspended particles, and temperature. The established regression equations could be used to predict the effect of road runoff on receiving environments.

  10. Contribution of tropical cyclones to global rainfall

    Science.gov (United States)

    Khouakhi, Abdou; Villarini, Gabriele; Vecchi, Gabriel; Smith, James

    2016-04-01

    Rainfall associated with tropical cyclones (TCs) can have both devastating and beneficial impacts in different parts of the world. In this work, daily precipitation and historical six-hour best track TC datasets are used to quantify the contribution of TCs to global rainfall. We select 18607 rain gauge stations with at least 25 complete (at least 330 measurements per year) years between 1970 and 2014. We consider rainfall associated with TCs if the center of circulation of the storm passed within a given distance from the rain gauge and within a given time window. Spatial and temporal sensitivity analyses are performed with varying time windows (same day, ±1 day) and buffer radii (400 km and 500 km) around each rain gauge. Results highlight regional differences in TC-induced rainfall. The highest TC-induced precipitation totals (400 to 600+ mm/year) are prevalent along eastern Asia, western and northeastern Australia, and in the western Pacific islands. Stations along the southeast of the U.S. coast and surrounding the Gulf of Mexico receive up to 200 mm/year of TC rainfall. The highest annual fractional contributions of TCs to total rainfall (from 35 to 50%) are recorded in stations located in northwestern Australia, southeastern China, the northern Philippines and the southern Mexico peninsula. Seasonally, the highest proportions (40 to 50%) are recorded along eastern Australia and Mauritius in winter, and in eastern Asia and Mexico in summer and autumn. Analyses of the relative contribution of TCs to extreme rainfall using annual maximum (AM) and peaks-over-threshold (POT) approaches indicate notable differences among regions. The highest TC-AM rainfall proportions (45 to 60%) are found in stations located in Japan, eastern China, the Philippines, eastern and western Australia. Substantial contributions (25 to 40% of extreme rainfall) are also recorded in stations located along the U.S. East Coast, the Gulf of Mexico, and the Mexico peninsula. We find similar

  11. 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.

  12. 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.

  13. 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)

  14. Performance analysis of 60-min to 1-min integration time rain rate conversion models in Malaysia

    Science.gov (United States)

    Ng, Yun-Yann; Singh, Mandeep Singh Jit; Thiruchelvam, Vinesh

    2018-01-01

    Utilizing the frequency band above 10 GHz is in focus nowadays as a result of the fast expansion of radio communication systems in Malaysia. However, rain fade is the critical factor in attenuation of signal propagation for frequencies above 10 GHz. Malaysia is located in a tropical and equatorial region with high rain intensity throughout the year, and this study will review rain distribution and evaluate the performance of 60-min to 1-min integration time rain rate conversion methods for Malaysia. Several conversion methods such as Segal, Chebil & Rahman, Burgeono, Emiliani, Lavergnat and Gole (LG), Simplified Moupfouma, Joo et al., fourth order polynomial fit and logarithmic model have been chosen to evaluate the performance to predict 1-min rain rate for 10 sites in Malaysia. After the completion of this research, the results show that Chebil & Rahman model, Lavergnat & Gole model, Fourth order polynomial fit and Logarithmic model have shown the best performances in 60-min to 1-min rain rate conversion over 10 sites. In conclusion, it is proven that there is no single model which can claim to perform the best across 10 sites. By averaging RMSE and SC-RMSE over 10 sites, Chebil and Rahman model is the best method.

  15. 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.

  16. 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.

  17. The odd man out? Might climate explain the lower tree alpha-diversity of African rain forests relative to Amazonian rain forests?

    NARCIS (Netherlands)

    Parmentier, I.; Malhi, Y.; Senterre, B.; Whittaker, R.J.; Alonso, A.; Balinga, M.P.B.; Bakayoko, A.; Bongers, F.J.J.M.; Chatelain, C.; Comiskey, J.; Cortay, R.; Djuikouo Kamdem, M.N.; Doucet, J.L.; Gauier, L.; Hawthorne, W.D.; Issembe, Y.A.; Kouamé, F.N.; Kouka, L.; Leal, M.E.; Lejoly, J.; Lewis, S.L.; Newbery, D.; Nusbaumer, L.; Parren, M.P.E.; Peh, K.S.H.; Phillips, O.L.; Sheil, D.; Sonké, B.; Sosef, M.S.M.; Sunderland, T.; Stropp, J.; Steege, ter H.; Swaine, M.; Tchouto, P.; Gemerden, van B.S.; Valkenburg, van J.; Wöll, H.

    2007-01-01

    1. Comparative analyses of diversity variation among and between regions allow testing of alternative explanatory models and ideas. Here, we explore the relationships between the tree alpha-diversity of small rain forest plots in Africa and in Amazonia and climatic variables, to test the explanatory

  18. 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.

  19. 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.

  20. Water's Journey from Rain to Stream in perspective

    Science.gov (United States)

    Rodhe, Allan; Grip, Harald

    2015-04-01

    The International Hydrological Decade (IHD) 1965-1974, sponsored by UNESCO, initiated a research effort for coordinating the fragmented branches of hydrology and for understanding and quantifying the hydrologic cycle on various scales, from continents to small catchments. One important part of the Swedish IHD-program was to quantify the terms of the water budget, including detailed data on soil water and groundwater storage dynamics, of several medium sized to small. As an outcome of these studies and subsequent process oriented studies, a new view of the runoff process in forested till soils was developed in the 1970's, stressing the dominating role of groundwater in delivering water to the streams and the usefulness of subdividing catchments into recharge and discharge areas for groundwater for understanding the flowpaths of water. This view contrasted with the general view among the public, and also among professionals within the field and in text books, according to which overland flow is the main process for runoff. With this latter view it would, for instance, not be possible to understand stream water chemistry, which had become an important question in a time of growing environmental concern. In order to decrease the time lag between research results and practice, the Swedish Natural Science Research Council initiated a text book project for presenting the recent results of hydrologic research on stream flow generation applied to Swedish conditions, and in 1985 our book "Water's Journey from Rain to Stream" was published. Founded on the basic principles for water storage and flow in soils, the book gives a general picture of the water flow through the forested till landscape, with separate chapters for recharge and discharge areas. Chemical processes along the flowpaths of water are treated and the book concludes with a few applications to current issues. The book is written in Swedish and the target audience is those working professionally with water and

  1. 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

  2. A Model for Estimation of Rain Rate on Tropical Land from TRMM Microwave Imager Radiometer Observations

    Science.gov (United States)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.; Kim, Kyu-Myong

    2004-01-01

    Over the tropical land regions observations of the 85 GHz brightness temperature (T(sub 85v)) made by the TRMM Microwave Imager (TMI) radiometer when analyzed with the help of rain rate (R(sub pR)) deduced from the TRMM Precipitation Radar (PR) indicate that there are two maxima in rain rate. One strong maximum occurs when T(sub 85) has a value of about 220 K and the other weaker one when T(sub 85v) is much colder approx. 150 K. Together with the help of earlier studies based on airborne Doppler Radar observations and radiative transfer theoretical simulations, we infer the maximum near 220 K is a result of relatively weak scattering due to super cooled rain drops and water coated ice hydrometeors associated with a developing thunderstorm (Cb) that has a strong updraft. The other maximum is associated with strong scattering due to ice particles that are formed when the updraft collapses and the rain from the Cb is transit2oning from convective type to stratiform type. Incorporating these ideas and with a view to improve the estimation of rain rate from existing operational method applicable to the tropical land areas, we have developed a rain retrieval model. This model utilizes two parameters, that have a horizontal scale of approx. 20km, deduced from the TMI measurements at 19, 21 and 37 GHz (T(sub 19v), T(sub 21v), T(sub 37v). The third parameter in the model, namely the horizontal gradient of brightness temperature within the 20 km scale, is deduced from TMI measurements at 85 GHz. Utilizing these parameters our retrieval model is formulated to yield instantaneous rain rate on a scale of 20 km and seasonal average on a mesoscale that agree well with that of the PR.

  3. [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.

  4. [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.

  5. Herbivory of tropical rain forest tree seedlings correlates with future mortality.

    Science.gov (United States)

    Eichhorn, Markus P; Nilus, Reuben; Compton, Stephen G; Hartley, Sue E; Burslem, David F R P

    2010-04-01

    Tree seedlings in tropical rain forests are subject to both damage from natural enemies and intense interspecific competition. This leads to a trade-off in investment between defense and growth, and it is likely that tree species specialized to particular habitats tailor this balance to correspond with local resource availability. It has also been suggested that differential herbivore impacts among tree species may drive habitat segregation, favoring species adapted to particular resource conditions. In order to test these predictions, a reciprocal transplant experiment in Sabah, Malaysia, was established with seedlings of five species of Dipterocarpaceae. These were specialized to either alluvial (Hopea nervosa, Parashorea tomentella) or sandstone soils (Shorea multiflora, H. beccariana), or were locally absent (S. fallax). A total of 3000 seedlings were planted in paired gap and understory plots in five sites on alluvial and sandstone soils. Half of all seedlings were fertilized. Seedling growth and mortality were recorded in regular samples over 3.5 years, and rates of insect herbivore damage were estimated from censuses of foliar tissue loss on marked mature leaves and available young leaves. Greater herbivory rates on mature leaves had no measurable effects on seedling growth but were associated with a significantly increased likelihood of mortality during the following year. In contrast, new-leaf herbivory rates correlated with neither growth nor mortality. There were no indications of differential impacts of herbivory among the five species, nor between experimental treatments. Herbivory was not shown to influence segregation of species between soil types, although it may contribute toward differential survival among light habitats. Natural rates of damage were substantially lower than have been shown to influence tree seedling growth and mortality in previous manipulative studies.

  6. The effect of particulate matter components on the acidity of rain in upper Silesia (Poland)

    Energy Technology Data Exchange (ETDEWEB)

    Hlawiczka, Stanislaw [Institute for Ecology of Industrial Areas, Katowice (Poland); Department of Environmental Protection and Engineering, Technical University of Czestochowa, Czestochowa (Poland); Korszun, Katarzyna [Institute for Ecology of Industrial Areas, Katowice (Poland)

    2012-07-15

    Analysis of data characterizing the chemical composition of atmospheric precipitation was presented, with an emphasis on components responsible for neutralization of rain acidity. For this purpose, chemometric methods were applied. Based on a principal component analysis (PCA) a strong correlation between precipitation pH and potassium and ammonium ions in the heating period (October-March) and potassium and sodium ions in the non-heating period (April-September) was observed. Additionally, a classification of eight variables, i.e., Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, Cl{sup -}, and NH{sub 4}{sup +} according to their similarities was made using a cluster analysis. Based on this study, two ions, potassium and ammonium, together with the pH value were classified into one group (cluster) in the heating period while in the non-heating period ions of potassium and sodium were clustered together with the pH. The results of the cluster analysis indicated that the selected ions contributed the most to the neutralization of the atmospheric precipitation acidity. This relationship was confirmed by a discriminant analysis in which potassium and ammonium ions were selected as components of the highest potential for precipitation classification according to its acidity degree. The relationship between the precipitation pH and the number of non-precipitation days preceding the precipitation was also analyzed. It was found that although the observed an increase of the pH value was not very high, nevertheless, the effect of the duration of the period preceding the precipitation on the pH value recorded on the day of the precipitation occurrence was quite evident. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. The effect of particulate matter components on the acidity of rain in upper Silesia (Poland)

    International Nuclear Information System (INIS)

    Hlawiczka, Stanislaw; Korszun, Katarzyna

    2012-01-01

    Analysis of data characterizing the chemical composition of atmospheric precipitation was presented, with an emphasis on components responsible for neutralization of rain acidity. For this purpose, chemometric methods were applied. Based on a principal component analysis (PCA) a strong correlation between precipitation pH and potassium and ammonium ions in the heating period (October-March) and potassium and sodium ions in the non-heating period (April-September) was observed. Additionally, a classification of eight variables, i.e., Na + , K + , Mg 2+ , Ca 2+ , SO 4 2- , NO 3 - , Cl - , and NH 4 + according to their similarities was made using a cluster analysis. Based on this study, two ions, potassium and ammonium, together with the pH value were classified into one group (cluster) in the heating period while in the non-heating period ions of potassium and sodium were clustered together with the pH. The results of the cluster analysis indicated that the selected ions contributed the most to the neutralization of the atmospheric precipitation acidity. This relationship was confirmed by a discriminant analysis in which potassium and ammonium ions were selected as components of the highest potential for precipitation classification according to its acidity degree. The relationship between the precipitation pH and the number of non-precipitation days preceding the precipitation was also analyzed. It was found that although the observed an increase of the pH value was not very high, nevertheless, the effect of the duration of the period preceding the precipitation on the pH value recorded on the day of the precipitation occurrence was quite evident. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Limited-area short-range ensemble predictions targeted for heavy rain in Europe

    Directory of Open Access Journals (Sweden)

    K. Sattler

    2005-01-01

    Full Text Available Inherent uncertainties in short-range quantitative precipitation forecasts (QPF from the high-resolution, limited-area numerical weather prediction model DMI-HIRLAM (LAM are addressed using two different approaches to creating a small ensemble of LAM simulations, with focus on prediction of extreme rainfall events over European river basins. The first ensemble type is designed to represent uncertainty in the atmospheric state of the initial condition and at the lateral LAM boundaries. The global ensemble prediction system (EPS from ECMWF serves as host model to the LAM and provides the state perturbations, from which a small set of significant members is selected. The significance is estimated on the basis of accumulated precipitation over a target area of interest, which contains the river basin(s under consideration. The selected members provide the initial and boundary data for the ensemble integration in the LAM. A second ensemble approach tries to address a portion of the model-inherent uncertainty responsible for errors in the forecasted precipitation field by utilising different parameterisation schemes for condensation and convection in the LAM. Three periods around historical heavy rain events that caused or contributed to disastrous river flooding in Europe are used to study the performance of the LAM ensemble designs. The three cases exhibit different dynamic and synoptic characteristics and provide an indication of the ensemble qualities in different weather situations. Precipitation analyses from the Deutsche Wetterdienst (DWD are used as the verifying reference and a comparison of daily rainfall amounts is referred to the respective river basins of the historical cases.

  9. 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

  10. 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

  11. 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

    The Water vapour Strong Lines at 183 GHz (183-WSL) algorithm is a method for the retrieval of rain rates and precipitation type classification (convectivestratiform), that makes use of the water vapor absorption lines centered at 183.31 GHz of the Advanced Microwave Sounding Unit module B (AMSU-B) and of the Microwave Humidity Sounder (MHS) flying on NOAA-15-18 and NOAA-19Metop-A satellite series, respectively. The characteristics of this algorithm were described in Part I of this paper together with comparisons against analogous precipitation products. The focus of Part II is the analysis of the performance of the 183-WSL technique based on surface radar measurements. The ground truth dataset consists of 2.5 years of rainfall intensity fields from the NIMROD European radar network which covers North-Western Europe. The investigation of the 183-WSL retrieval performance is based on a twofold approach: 1) the dichotomous statistic is used to evaluate the capabilities of the method to identify rain and no-rain clouds; 2) the accuracy statistic is applied to quantify the errors in the estimation of rain rates.The results reveal that the 183-WSL technique shows good skills in the detection of rainno-rain areas and in the quantification of rain rate intensities. The categorical analysis shows annual values of the POD, FAR and HK indices varying in the range 0.80-0.82, 0.330.36 and 0.39-0.46, respectively. The RMSE value is 2.8 millimeters per hour for the whole period despite an overestimation in the retrieved rain rates. Of note is the distribution of the 183-WSL monthly mean rain rate with respect to radar: the seasonal fluctuations of the average rainfalls measured by radar are reproduced by the 183-WSL. However, the retrieval method appears to suffer for the winter seasonal conditions especially when the soil is partially frozen and the surface emissivity drastically changes. This fact is verified observing the discrepancy distribution diagrams where2the 183-WSL

  12. Explosive radiation of Malpighiales supports a mid-cretaceous origin of modern tropical rain forests.

    Science.gov (United States)

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

    2005-03-01

    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, provide new tests of these hypotheses. We estimate that all 28 major lineages (i.e., traditionally recognized families) within this clade originated in tropical rain forest well before the Tertiary, mostly during the Albian and Cenomanian (112-94 Ma). Their rapid rise in the mid-Cretaceous may have resulted from the origin of adaptations to survive and reproduce under a closed forest canopy. This pattern may also be paralleled by other similarly diverse lineages and supports fossil indications that closed-canopy tropical rain forests existed well before the K/T boundary. This case illustrates that dated phylogenies can provide an important new source of evidence bearing on the timing of major environmental changes, which may be especially useful when fossil evidence is limited or controversial.

  13. 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.

  14. Investigation of formaldehyde pollution of tap water and rain water using a novel visual colorimetry.

    Science.gov (United States)

    Murai, K; Okano, M; Kuramitz, H; Hata, N; Kawakami, T; Taguchi, S

    2008-01-01

    The pollution of tap water and rain water with formaldehyde in Toyama Pref., Japan was investigated by means of a simple, rapid and cost-effective visual colorimetry developed by us. The levels of formaldehyde in three tap waters from different sources of dams on mountainside and a well-water pumped in urban area in Toyama Pref. were lower than 0.01 mg L(-1) that was the detection limit of the colorimetry. On the other hand, rain waters were seriously polluted with formaldehyde. Rain waters were sampled from three different sites (urban area, top of hill and industrial area) in Toyama Pref. from autumn to winter in 2006. The levels of formaldehyde in the rain waters ranged from 0.07 to 0.30 mg L(-1). The analytical results by the visual colorimetry were in good agreement with those obtained by GC-MS method. It was confirmed that the colorimetry is excellent for practical use for the determination of formaldehyde. It must be concerned about the pollution of rainwater with formaldehyde, when rain water is applied for tap water and miscellaneous purpose. Copyright IWA Publishing 2008.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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)

  20. Effect of simulated acid rain on fluorine mobility and the bacterial community of phosphogypsum.

    Science.gov (United States)

    Wang, Mei; Tang, Ya; Anderson, Christopher W N; Jeyakumar, Paramsothy; Yang, Jinyan

    2018-03-21

    Contamination of soil and water with fluorine (F) leached from phosphogypsum (PG) stacks is a global environmental issue. Millions of tons of PG is produced each year as a by-product of fertilizer manufacture, and in China, weathering is exacerbated by acid rain. In this work, column leaching experiments using simulated acid rain were run to evaluate the mobility of F and the impact of weathering on native bacterial community composition in PG. After a simulated summer rainfall, 2.42-3.05 wt% of the total F content of PG was leached and the F concentration in leachate was above the quality standard for surface water and groundwater in China. Acid rain had no significant effect on the movement of F in PG. A higher concentration of F was observed at the bottom than the top section of PG columns suggesting mobility and reprecipitation of F. Throughout the simulation, the PG was environmentally safe according the TCLP testing. The dominant bacteria in PG were from the Enterococcus and Bacillus genus. Bacterial community composition in PG leached by simulated acid rain (pH 3.03) was more abundant than at pH 6.88. Information on F mobility and bacterial community in PG under conditions of simulated rain is relevant to management of environmental risk in stockpiled PG waste.

  1. Prolonged acid rain facilitates soil organic carbon accumulation in a mature forest in Southern China.

    Science.gov (United States)

    Wu, Jianping; Liang, Guohua; Hui, Dafeng; Deng, Qi; Xiong, Xin; Qiu, Qingyan; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2016-02-15

    With the continuing increase in anthropogenic activities, acid rain remains a serious environmental threat, especially in the fast developing areas such as southern China. To detect how prolonged deposition of acid rain would influence soil organic carbon accumulation in mature subtropical forests, we conducted a field experiment with simulated acid rain (SAR) treatments in a monsoon evergreen broadleaf forest at Dinghushan National Nature Reserve in southern China. Four levels of SAR treatments were set by irrigating plants with water of different pH values: CK (the control, local lake water, pH ≈ 4.5), T1 (water pH=4.0), T2 (water pH=3.5), and T3 (water pH=3.0). Results showed reduced pH measurements in the topsoil exposed to simulated acid rains due to soil acidification. Soil respiration, soil microbial biomass and litter decomposition rates were significantly decreased by the SAR treatments. As a result, T3 treatment significantly increased the total organic carbon by 24.5% in the topsoil compared to the control. Furthermore, surface soil became more stable as more recalcitrant organic matter was generated under the SAR treatments. Our results suggest that prolonged acid rain exposure may have the potential to facilitate soil organic carbon accumulation in the subtropical forest in southern China. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Chemical characterization of fog and rain water collected at the eastern Andes cordillera

    Directory of Open Access Journals (Sweden)

    E. Beiderwieden

    2005-01-01

    Full Text Available 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.

  3. 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.

  4. 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.

  5. Simple Rain-Shelter Cultivation Prolongs Accumulation Period of Anthocyanins in Wine Grape Berries

    Directory of Open Access Journals (Sweden)

    Xiao-Xi Li

    2014-09-01

    Full Text Available Simple rain-shelter cultivation is normally applied during the grape growth season in continental monsoon climates aiming to reduce the occurrence of diseases caused by excessive rainfall. However, whether or not this cultivation practice affects the composition and concentration of phenolic compounds in wine grapes remains unclear. The objective of this study was to investigate the effect of rain-shelter cultivation on the accumulation of anthocyanins in wine grapes (Vitis vinifera L. Cabernet Sauvignon grown in eastern China. The results showed that rain-shelter cultivation, compared with the open-field, extended the period of rapid accumulation of sugar, increased the soluble solid content in the grape berries, and delayed the senescence of the green leaves at harvest. The concentrations of most anthocyanins were significantly enhanced in the rain-shelter cultivated grapes, and their content increases were closely correlated with the accumulation of sugar. However, the compositions of anthocyanins in the berries were not altered. Correspondingly, the expressions of VvF3'H, VvF3'5'H, and VvUFGT were greatly up-regulated and this rising trend appeared to continue until berry maturation. These results suggested that rain-shelter cultivation might help to improve the quality of wine grape berries by prolonging the life of functional leaves and hence increasing the assimilation products.

  6. 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.

  7. 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.

  8. Rain detection over land surfaces using passive microwave satellite data

    NARCIS (Netherlands)

    Bauer, P.; Burose, D.; Schulz, J.

    2002-01-01

    An algorithm is presented for the detection of surface rainfall using passive microwave measurements by satellite radiometers. The technique consists of a two-stage approach to distinguish precipitation signatures from other effects: (1) Contributions from slowly varying parameters (surface type and

  9. Decoupled leaf and stem economics in rain forest trees

    NARCIS (Netherlands)

    Baraloto, C.; Paine, C.E.T.; Poorter, L.; Beauchene, J.; Bonal, D.; Domenach, A.M.; Herault, B.; Patiño, S.; Roggy, J.C.; Chave, J.

    2010-01-01

    Cross-species analyses of plant functional traits have shed light on factors contributing to differences in performance and distribution, but to date most studies have focused on either leaves or stems. We extend these tissue-specific analyses of functional strategy towards a whole-plant approach by

  10. 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.

  11. The influence of rain and clouds on a satellite dual frequency radar altimeter system operating at 13 and 35 GHz

    Science.gov (United States)

    Walsh, E. J.; Monaldo, F. M.; Goldhirsh, J.

    1983-01-01

    The effects of inhomogeneous spatial attenuation resulting from clouds and rain on the altimeter estimate of the range to mean sea level are modelled. It is demonstrated that typical cloud and rain attenuation variability at commonly expected spatial scales can significantly degrade altimeter range precision. Rain cell and cloud scale sizes and attenuations are considered as factors. The model simulation of altimeter signature distortion is described, and the distortion of individual radar pulse waveforms by different spatial scales of attenuation is considered. Examples of range errors found for models of a single cloud, a rain cell, and cloud streets are discussed.

  12. The use of permit markets for incorporating source location. The case of acid rain in Europe

    International Nuclear Information System (INIS)

    Steiner, U.; Tinggaard Svendsen, G.

    1997-01-01

    The paper shows that cost-effective involvement of the source location involves utmost difficulty in practice. Based on the RAINS model, it is recommended that source location should be ignored in a European market for SO 2 , as is the case in the US Acid Rain Program. The RAINS-model predicts a cost-saving of 37 percent but an average loss of 2 percent in ecological protection. To overcome this reduction in protection, we recommend that some of the large cost-savings should be reallocated in further overall reduction and that the countries suffering the most from introducing the permit-market should be compensated by receiving extra permits in the initial distribution. (au)

  13. Estimate of annual daily maximum rainfall and intense rain equation for the Formiga municipality, MG, Brazil

    Directory of Open Access Journals (Sweden)

    Giovana Mara Rodrigues Borges

    2016-11-01

    Full Text Available Knowledge of the probabilistic behavior of rainfall is extremely important to the design of drainage systems, dam spillways, and other hydraulic projects. This study therefore examined statistical models to predict annual daily maximum rainfall as well as models of heavy rain for the city of Formiga - MG. To do this, annual maximum daily rainfall data were ranked in decreasing order that best describes the statistical distribution by exceedance probability. Daily rainfall disaggregation methodology was used for the intense rain model studies and adjusted with Intensity-Duration-Frequency (IDF and Exponential models. The study found that the Gumbel model better adhered to the data regarding observed frequency as indicated by the Chi-squared test, and that the exponential model best conforms to the observed data to predict intense rains.

  14. A Matérn model of the spatial covariance structure of point rain rates

    KAUST Repository

    Sun, Ying

    2014-07-15

    It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.

  15. Model radioisotope experiments on the influence of acid rain on 65Zn binding with humic acid

    International Nuclear Information System (INIS)

    Koczorowska, E.; Mieloch, M.; Slawinski, J.

    2002-01-01

    Acid rain formed first of all from sulfur oxide emitted by natural and anthropogenic sources, may change the biological equilibrium and the metal stoppage in the soil. The model experiments were performed to determine the influence of acid rain on zinc bond with humic acid (HA). The samples were prepared in glass columns with quartz sand and overlaid HA or HA + 65 Zn radioisotope that simulates natural conditions. Then, solutions of H 2 SO 4 were introduced into the sand - HA layer. Zinc was washed with diluted (10 -4 - 10 -3 M) sulphuric acid as a simulation of acid rain. The results help to evaluate the migration behaviour of zinc in the presence of HA and H 2 SO 4 . The model studies illustrate the considerable influence of sulfuric acid on chemical degradation of HA. (author)

  16. Model study of acid rain effect on adsorption of trace elements on soils using a multitracer

    International Nuclear Information System (INIS)

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

    1998-01-01

    Using a radioactive multitracer and model acid rain (HCl or H 2 SO 4 solution), batch experiments were performed to examine the pH effect on the adsorption-desorption equilibrium of 16 elements on soils as a model study of an acid rain effect. Kaolin, black soil (original and with organic matter almost removed) and Kureha soil (original and with organic matter almost removed) were used as adsorbents. Characteristic dependence on the pH value of the suspension was observed for the adsorption of the elements on kaolin and the soils. The results of this model study indicate that acid rain decreases the retention of cations, while it increases or does not change the adsorption of anions on soils. Organic matter in soils has a positive effect on the extent of adsorption of most elements investigated. (author)

  17. A Matérn model of the spatial covariance structure of point rain rates

    KAUST Repository

    Sun, Ying; Bowman, Kenneth P.; Genton, Marc G.; Tokay, Ali

    2014-01-01

    It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.

  18. Study on effects of solar radiation and rain on shrinkage, shrinkage cracking and creep of concrete

    International Nuclear Information System (INIS)

    Asamoto, Shingo; Ohtsuka, Ayumu; Kuwahara, Yuta; Miura, Chikako

    2011-01-01

    In this paper, the effects of actual environmental actions on shrinkage, creep and shrinkage cracking of concrete are studied comprehensively. Prismatic specimens of plain concrete were exposed to three sets of artificial outdoor conditions with or without solar radiation and rain to examine the shrinkage. For the purpose of studying shrinkage cracking behavior, prismatic concrete specimens with reinforcing steel were also subjected to the above conditions at the same time. The shrinkage behavior is described focusing on the effects of solar radiation and rain based on the moisture loss. The significant environment actions to induce shrinkage cracks are investigated from viewpoints of the amount of the shrinkage and the tensile strength. Finally, specific compressive creep behavior according to solar radiation and rainfall is discussed. It is found that rain can greatly inhibit the progresses of concrete shrinkage and creep while solar radiation is likely to promote shrinkage cracking and creep.

  19. [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.

  20. Characteristic Rain Events – A tool to enhance amenity values in SUDS-design

    DEFF Research Database (Denmark)

    Smit Andersen, Jonas; Lerer, Sara Maria; Sørup, Hjalte Jomo Danielsen

    2016-01-01

    To overcome the challenge of designing good-looking open detention/retention areas in the urban landscape that can manage stormwater runoff from both the large, rare events and the frequent smaller events without looking empty and oversized a new approach referred to as Characteristic Rain Events...... (CRE) is proposed. The idea of the CRE is to demonstrate the water dynamics of a detention/retention area in a number of characteristic situations, in this way allowing the designer to work in a more tangible way with the design.Based on historical rain series single events are selected, representing...... the day-to-day domain, the design domain and the extreme domain as defined in the Three Point Approach (3PA). In this paper the ability of CRE to unfold the water dynamics of a detention/retention area is investigated by applying four CRE to a fictive rain garden including frequent, short event...

  1. Acid Rain Phenomenon in Niger Delta Region of Nigeria: Economic, Biodiversity, and Public Health Concern

    Directory of Open Access Journals (Sweden)

    J. K. C. Nduka

    2008-01-01

    Full Text Available Rain samples were collected from Warri and Port Harcourt, two major oil-producing cities of Nigeria in April-June, July-August, and September-October 2005 and 2006. Awka, a “non-oil” city was used as control. Samples were collected from three points, using clean plastic basins fastened to a table, 2 m above ground level and 115 m away from tall buildings and trees. Water samples were filtered and acidity determined using digital pHmeter. The results show that the rain samples were acidic. The pH values for the 2 years under study show that the rainfall in Warri was more acidic than that of Port Harcourt. Oil exploration and other anthropogenic sources may be responsible for the acid rain in the Niger Delta region of Nigeria.

  2. A COMPARATIVE STOCHASTIC FRONTIER ANALYSIS OF IRRIGATED AND RAIN-FED POTATO FARMS IN EASTERN ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Kumilachew Alamerie Melesse

    2015-12-01

    Full Text Available Irrigation development has been considered as one of the viable strategies for achieving food security. Accordingly, the government of Ethiopia has been increasing water resource development and utilization. However, to what extent the irrigation users are better off than rainfall dependent counterparts on their technical effi ciency (TE and variability in productivity among the farmers is not well known. Therefore, this study compared the technical effi ciency of farmers who are producing potato under irrigation and through rainfall in Eastern Ethiopia. Propensity Score Matching was applied to select irrigated farms with comparable attributes to rain-fed farms to see the true effi ciency diff erences between the two groups. Cobb-Douglas production function was fi tted using the stochastic production frontier for both irrigated and rain fed farming. The result indicated that irrigated farms have high ineffi ciencies compared with the rain-fed farms. This indicates the existence of considerable potential for increasing output by improving the effi ciency of irrigated farms than rain-fed farms. Among the factors hypothesized to determine the level of TE, landholding, family size and extension contact were found to have a signifi cant eff ect on irrigated farms whereas, landholding, non/off income, farm income, livestock size and extension contact were the determinants in rain-fed farms. This indicates that factors that aff ect technical effi - ciency in irrigated farms are not necessarily the same as rain fed farms. Therefore, it is important to consider both farms groups in evaluating strategies aimed at improving technical effi ciency of smallholder farmers

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Association of Acute Radiation Syndrome and Rain after the Bombings in Atomic Bomb Survivors.

    Science.gov (United States)

    Ozasa, K; Sakata, R; Cullings, H M; Grant, E J

    2016-06-01

    Acute radiation-induced symptoms reported in survivors after the atomic bombings in Hiroshima and Nagasaki have been suspected to be associated with rain that fell after the explosions, but this association has not been evaluated in an epidemiological study that considers the effects of the direct dose from the atomic bombs and other factors. The aim of this study was to evaluate this association using information from a fixed cohort, comprised of 93,741 members of the Life Span Study who were in the city at the time of the bombing. Information on acute symptoms and exposure to rain was collected in surveys conducted by interviewers, primarily in the 1950s. The proportion of survivors developing severe epilation was around 60% at levels of direct radiation doses of 3 Gy or higher and less than 0.2% at levels <0.005 Gy regardless of reported rain exposure status. The low prevalence of acute symptoms at low direct doses indicates that the reported fallout rain was not homogeneously radioactive at a level sufficient to cause a substantial probability of acute symptoms. We observed that the proportion of reported acute symptoms was slightly higher among those who reported rain exposure in some subgroups, however, suggestions that rain was the cause of these reported symptoms are not supported by analyses specific to the known areas of radioactive fallout. Misclassification of exposure and outcome, including symptoms due to other causes and recall bias, appears to be a more plausible explanation. However, the insufficient and retrospective nature of the available data limited our ability to quantify the attribution to those possible causes.

  8. 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.

  9. A Model for Estimation of Rain Rate on Tropical Land from TRMM Microwave Imager Radiometer Observations

    OpenAIRE

    C., PRABHAKARA; R., IACOVAZZI; J. M., YOO; K. M., KIM; NASA Goddard Space Flight Center; Center for Research on the Changing Earth System; EWHA Womans University; Science Systems and Applications, Inc.

    2005-01-01

    Over the tropical land regions scatter plots of the rain rate (R_), deduced from the TRMM Precipitation Radar (PR) versus the observed 85GHz brightness temperature (T_) made by the TRMM Microwave Imager (TMI) radiometer, for a period of a season over a given geographic region of 3°×5°(lat×lon), indicate that there are two maxima in rain rate. One strong maximum occurs when T_ has a value of about 220K, and the other weaker one when T_ is much colder ~150K. Also these two maxima are vividly re...

  10. Wind-driven rain as a boundary condition for HAM simulations: analysis of simplified modelling approaches

    DEFF Research Database (Denmark)

    Janssen, Hans; Blocken, Bert; Roels, Staf

    2007-01-01

    While the numerical simulation of moisture transfer inside building components is currently undergoing standardisation, the modelling of the atmospheric boundary conditions has received far less attention. This article analyses the modelling of the wind-driven-rain load on building facades...... though: the full variability with the perpendicular wind speed and horizontal rain intensity should be preserved, where feasible, for improved estimations of the moisture transfer in building components. In the concluding section, it is moreover shown that the dependence of the surface moisture transfer...

  11. Validation of the H-SAF precipitation product H03 over Greece using rain gauge data

    Science.gov (United States)

    Feidas, H.; Porcu, F.; Puca, S.; Rinollo, A.; Lagouvardos, C.; Kotroni, V.

    2018-01-01

    This paper presents an extensive validation of the combined infrared/microwave H-SAF (EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management) precipitation product H03, for a 1-year period, using gauge observations from a relatively dense network of 233 stations over Greece. First, the quality of the interpolated data used to validate the precipitation product is assessed and a quality index is constructed based on parameters such as the density of the station network and the orography. Then, a validation analysis is conducted based on comparisons of satellite (H03) with interpolated rain gauge data to produce continuous and multi-categorical statistics at monthly and annual timescales by taking into account the different geophysical characteristics of the terrain (land, coast, sea, elevation). Finally, the impact of the quality of interpolated data on the validation statistics is examined in terms of different configurations of the interpolation model and the rain gauge network characteristics used in the interpolation. The possibility of using a quality index of the interpolated data as a filter in the validation procedure is also investigated. The continuous validation statistics show yearly root mean squared error (RMSE) and mean absolute error (MAE) corresponding to the 225 and 105 % of the mean rain rate, respectively. Mean error (ME) indicates a slight overall tendency for underestimation of the rain gauge rates, which takes large values for the high rain rates. In general, the H03 algorithm cannot retrieve very well the light (10 mm/h) precipitation. The poor correlation between satellite and gauge data points to algorithm problems in co-locating precipitation patterns. Seasonal comparison shows that retrieval errors are lower for cold months than in the summer months of the year. The multi-categorical statistics indicate that the H03 algorithm is able to discriminate efficiently the rain from the no rain events

  12. 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.

  13. [Seasonal variation of soil respiration and its components in tropical rain forest and rubber plantation in Xishuangbanna, Yunnan].

    Science.gov (United States)

    Lu, Hua-Zheng; Sha, Li-Qing; Wang, Jun; Hu, Wen-Yan; Wu, Bing-Xia

    2009-10-01

    By using trenching method and infrared gas analyzer, this paper studied the seasonal variation of soil respiration (SR), including root respiration (RR) and heterotrophic respiration (HR), in tropical seasonal rain forest (RF) and rubber (Hevea brasiliensis) plantation (RP) in Xishuangbanna of Yunnan, China. The results showed that the SR and HR rates were significantly higher in RF than in RP (P dry-hot season > foggy season, but the RR rate was rainy season > foggy season > dry-hot season in RF, and foggy season > rainy season > dry-hot season in RP. The contribution of RR to SR in RF (29%) was much lower than that in RP (42%, P < 0.01), while the contribution of HR to SR was 71% in RF and 58% in RP. When the soil temperature at 5 cm depth varied from 12 degrees C to 32 degrees C, the Q10 values for SR, HR, and RR rates were higher in RF than in RP. HR had the highest Q10 value, while RR had the lowest one.

  14. Humidity estimate for the middle Eocene Arctic rain forest

    Science.gov (United States)

    Jahren, A. Hope; Silveira Lobo Sternberg, Leonel

    2003-05-01

    The exquisite preservation of fossilized Metasequoia trees that grew near 80°N latitude during the middle Eocene (ca. 45 Ma) in Nunavut, Canada, allowed for δD and δ18O analyses of cellulose, techniques previously restricted to wood <30,000 yr old. From the isotopic results, we determined that the middle Eocene Arctic atmosphere contained ˜2× the water found in the region's atmosphere today. This water vapor contributed to a middle Eocene greenhouse effect that insulated the polar region during dark polar winters.

  15. Rain-season trends in precipitation and their effect in different climate regions of China during 1961-2008

    International Nuclear Information System (INIS)

    Song Yanling; Achberger, Christine; Linderholm, Hans W

    2011-01-01

    Using high-quality precipitation data from 524 stations, the trends of a set of precipitation variables during the main rain season (May-September) from 1961 to 2008 for different climate regions in China were analysed. However, different characteristics were displayed in different regions of China. In most temperate monsoon regions (north-eastern China), total rain-season precipitation and precipitation days showed decreasing trends; positive tendencies in precipitation intensity were, however, noted for most stations in this region. It is suggested that the decrease in rain-season precipitation is mainly related to there being fewer rain days and a change towards drier conditions in north-eastern China, and as a result, the available water resources have been negatively affected in the temperate monsoon regions. In most subtropical and tropical monsoon climate regions (south-eastern China), the rain-season precipitation and precipitation days (11-50, with > 50 mm) showed slightly positive trends. However, precipitation days with ≤ 10 mm decreased in these regions. Changes towards wetter conditions in this area, together with more frequent heavy rainfall events causing floods, have a severe impact on peoples' lives and socio-economic development. In general, the rain-season precipitation, precipitation days and rain-season precipitation intensity had all increased in the temperate continental and plateau/mountain regions of western China. This increase in rain-season precipitation has been favourable to pasture growth.

  16. Impact of simulated acid rain on trace metals and aluminum leaching in latosol from Guangdong Province, China

    Science.gov (United States)

    Jia-En Zhang; Jiayu Yu; Ying Ouyang; Huaqin. Xu

    2014-01-01

    Acid rain is one of the most serious ecological and environmental problems worldwide. This study investigated the impacts of simulated acid rain (SAR) upon leaching of trace metals and aluminum (Al) from a soil. Soil pot leaching experiments were performed to investigate the impacts of SAR at five different pH levels (or treatments) over a 34-day period upon the...

  17. Impact of wind on the spatial distribution of rain over micro-scale topography : numerical modelling and experimental verification

    NARCIS (Netherlands)

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

    2006-01-01

    The wind-driven-rain effect refers to the redistribution of rainfall over micro-scale topography due to the existence of local perturbed wind-flow patterns. Rainfall measurements reported in the literature point to the fact that the wind-driven-rain distribution can show large variations over

  18. Farmers’ knowledge, use and preferences of parasitic weed management strategies in rain-fed rice production systems

    NARCIS (Netherlands)

    Tippe, Dennis E.; Rodenburg, Jonne; Schut, Marc; Ast, van Aad; Kayeke, Juma; Bastiaans, Lammert

    2017-01-01

    Rain-fed rice production in sub-Saharan Africa is often hampered by parasitic weeds. This study assessed farmers’ awareness, use, preference and adoption criteria of parasitic weed management practices in rain-fed rice production environments in Tanzania. Surveys and workshops were organized in

  19. 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.

  20. 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…

  1. The making and prevention of rain amongst the Pedi tribe of South ...

    African Journals Online (AJOL)

    2013-02-11

    Feb 11, 2013 ... which are practised among the Pedi tribes – also called the Northern-Sotho speaking ... against the well being of a southern African society [is a lack of rain]. .... generation], meaning that it is the responsibility of the older.

  2. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity

    NARCIS (Netherlands)

    Gemerden, van B.S.; Olff, H.; Parren, M.P.E.; Bongers, F.J.J.M.

    2003-01-01

    Aim Tropical rain forests are often regarded as pristine and undisturbed by humans. In Central Africa, community-wide disturbances by natural causes are rare and therefore current theory predicts that natural gap phase dynamics structure tree species composition and diversity. However, the dominant

  3. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity

    NARCIS (Netherlands)

    Gemerden, Barend S. van; Olff, Han; Parren, Marc P.E.; Bongers, Frans

    2003-01-01

    Aim: Tropical rain forests are often regarded as pristine and undisturbed by humans. In Central Africa, community-wide disturbances by natural causes are rare and therefore current theory predicts that natural gap phase dynamics structure tree species composition and diversity. However, the dominant

  4. Variation in photosynthetic light-use efficiency in a mountainous tropical rain forest in Indonesia

    DEFF Research Database (Denmark)

    Ibrom, Andreas; Oltchev, A.; June, T.

    2008-01-01

    in remote tropical areas. We used a 16-month continuous CO2 flux and meteorological dataset from a mountainous tropical rain forest in central Sulawesi, Indonesia to derive values of epsilon(Pg). and to investigate the relationship between P-g and Q(abs). Absorption was estimated with a 1D SVAT model from...

  5. The Potential of in situ Rain Water Harvesting for Water Resources ...

    African Journals Online (AJOL)

    Key words: In situ Rain water harvesting, Malaria, Anopheles arabiensis, Tigray, Ethiopia. 1. INTRODUCTION .... heating the water in the vials to be preserved in 70% alcohol after draining the excess water. The immature ..... (eds.). Integrated water and land management research and capacity building priorities for Ethiopia.

  6. The northern flying squirrel as an indicator species of temperate rain forest: test of an hypothesis.

    Science.gov (United States)

    Winston P. Smith; Scott M. Gende; Jeffrey V. Nichols

    2005-01-01

    Management indicator species (MIS) often are selected because their life history and demographics are thought to reflect a suite of ecosystem conditions that are too difficult or costly to measure directly. The northern flying squirrel (Glaucomys sabrinus) has been proposed as an MIS of temperate rain forest of southeastern Alaska based on previous...

  7. Rain Forest Tourism - Estimating the Benefits of Tourism Development in a New National Park in Madagascar

    Science.gov (United States)

    D. Evan Mercer; R. Kramer; N. Sharma

    1995-01-01

    Travel cost and contingent valuation methods are applied to the problem of estimating the potential consumer surplus available to international nature tourists from a rain forest conservation project in Madagascar. Data are derived from surveys of nature tourists in Madagascar and international, nature tourism professionals in the U.S. and Europe. Typical trip travel...

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

    Science.gov (United States)

    Dove, Jane

    1996-01-01

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

  9. The Potential of in situ Rain Water Harvesting for Water Resources ...

    African Journals Online (AJOL)

    The role of in situ rain water harvesting (RWH) in water resources conservation is well recognized in semiarid areas, such as the highlands of northern Ethiopia. However, in fringe areas of malaria endemicity, the potential impact of such schemes on vector populations and malaria transmission is not well documented.

  10. Foliar and ecosystem respiration in an old-growth tropical rain forest

    Science.gov (United States)

    Molly A. Cavaleri; Steven F. Oberbauer; Michael G. Ryan

    2008-01-01

    Foliar respiration is a major component of ecosystem respiration, yet extrapolations are often uncertain in tropical forests because of indirect estimates of leaf area index (LAI).A portable tower was used to directly measure LAI and night-time foliar respiration from 52 vertical transects throughout an old-growth tropical rain forest in Costa Rica. In this study, we (...

  11. Protecting apple trees from rain –better fruit quality and maintenance of yield

    OpenAIRE

    Kjaer, Katrine Heinsvig

    2016-01-01

    Plastic rain shields reduce the leaf and fruit wetness and protect apple trees against major leaf diseases and hail damage. Shielding the trees may reduce incoming radiation, especially in the ultraviolet (UV) region of the light spectrum, and affect the microclimate and photosynthesis.

  12. 78 FR 64496 - Acid Rain Program: Notice of Annual Adjustment Factors for Excess Emissions Penalty

    Science.gov (United States)

    2013-10-29

    ... Factors for Excess Emissions Penalty AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of annual adjustment factors for excess emissions penalty. SUMMARY: The Acid Rain Program under title IV of... excess tons emitted times $2,000 as adjusted by an annual adjustment factor, which must be published in...

  13. Study of the concentration of 7 Be in samples of rain water

    International Nuclear Information System (INIS)

    Quintero P, E.; Rojas M, V.P.

    2004-01-01

    This work shows the methodology carried out for the determination of 7 Be in samples of rain water and the obtained results of the concentration of having said radionuclide in this sampled matrix during the last five years in the Nuclear Center of Mexico. (Author)

  14. ANALYSIS OF DEBRIS FLOW DISASTER DUE TO HEAVY RAIN BY X-BAND MP RADAR DATA

    Directory of Open Access Journals (Sweden)

    M. Nishio

    2016-06-01

    Full Text Available On August 20 of 2014, Hiroshima City (Japan was struck by local heavy rain from an autumnal rain front. The resultant debris flow disaster claimed 75 victims and destroyed many buildings. From 1:30 am to 4:30 am on August 20, the accumulated rainfall in Hiroshima City exceeded 200 mm. Serious damage occurred in the Asakita and Asaminami wards of Hiroshima City. As a disaster prevention measure, local heavy rain (localized torrential rains is usually observed by the Automated Meteorological Data Acquisition System (AMeDAS operated by the Japan Meteorological Agency (JMA and by the C-band radar operated by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT of Japan, with spatial resolutions of 2.5 km and 1 km, respectively. The new X-band MP radar system enables more detailed rainfall observations than the C-band radar. In fact, this radar can observe local rainfall throughout Japan in near-real time over a minimum mesh size of 250 m. A fine-scale accumulated rainfall monitoring system is crucial for disaster prevention, and potential disasters can be alerted by the hazard levels of the accumulated rainfall.

  15. Dancing in the Rain: Leading with Compassion, Vitality, and Mindfulness in Education

    Science.gov (United States)

    Murphy, Jerome T.

    2016-01-01

    "Dancing in the Rain" offers a lively and accessible guide aimed at helping education leaders thrive under pressure by developing the inner strengths of mindfulness and self-compassion, expressing emotions wisely, and maintaining a clear focus on the values that matter most. Jerome T. Murphy, a scholar and former dean who has written and…

  16. Perfluoroalkyl substances in the Maltese Environment - (I) Surface water and rain water

    NARCIS (Netherlands)

    Sammut, G.; Sinagra, E.; Helmus, R.; de Voogt, P.

    2017-01-01

    The presence of perfluoroalkyl substances (PFASs) in rain water on the Maltese Islands is reported here for the first time and an extensive survey of these substances in surface water also reported. The Maltese archipelago lies at the centre of the Mediterranean Sea and consists of three main

  17. 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.

  18. State Regulatory responses to acid rain: Implications for electric utility operations

    International Nuclear Information System (INIS)

    Nagelhout, M.

    1990-01-01

    This article discusses the state regulatory responses to acid rain legislation and how this will affect electric utility operations. Topics discusses include planning and fuel procurement practices, least-cost planning, long-term supply contracts, fuel mix, cogeneration and small power production, qualifying facility contracts, avoided costs, environmental impact, lobbying expense, bill inserts, and forecasting models

  19. A High Precision $3.50 Open Source 3D Printed Rain Gauge Calibrator

    Science.gov (United States)

    Lopez Alcala, J. M.; Udell, C.; Selker, J. S.

    2017-12-01

    Currently available rain gauge calibrators tend to be designed for specific rain gauges, are expensive, employ low-precision water reservoirs, and do not offer the flexibility needed to test the ever more popular small-aperture rain gauges. The objective of this project was to develop and validate a freely downloadable, open-source, 3D printed rain gauge calibrator that can be adjusted for a wide range of gauges. The proposed calibrator provides for applying low, medium, and high intensity flow, and allows the user to modify the design to conform to unique system specifications based on parametric design, which may be modified and printed using CAD software. To overcome the fact that different 3D printers yield different print qualities, we devised a simple post-printing step that controlled critical dimensions to assure robust performance. Specifically, the three orifices of the calibrator are drilled to reach the three target flow rates. Laboratory tests showed that flow rates were consistent between prints, and between trials of each part, while the total applied water was precisely controlled by the use of a volumetric flask as the reservoir.

  20. 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.

  1. Architecture of 53 rain forest tree species differing in adult stature and shade tolerance

    NARCIS (Netherlands)

    Poorter, L.; Bongers, F.J.J.M.; Sterck, F.J.; Wöll, H.

    2003-01-01

    Tree architecture determines a tree's light capture, stability, and efficiency of crown growth. The hypothesis that light demand and adult stature of tree species within a community, independently of each other, determine species' architectural traits was tested by comparing 53 Liberian rain forest

  2. Performance of an alpha-vane and pitot tube in simulated heavy rain environment

    Science.gov (United States)

    Luers, J. K.; Fiscus, I. B.

    1985-01-01

    Experimental tests were conducted in the UDRI Environmental Wind/Rain Tunnel to establish the performance of an alpha-vane, that measures angle of attack, in a simulated heavy rain environment. The tests consisted of emersing the alpha-vane in an airstream with a concurrent water spray penetrating vertically through the airstream. The direction of the spray was varied to make an angle of 5.8 to 18 deg with the airstream direction in order to simulate the conditions that occur when an aircraft lands in a heavy rain environment. Rainrates simulated varied from 1000 to 1200 mm/hr which are the most severe ever expected to be encountered by an aircraft over even a 30 second period. Tunnel airspeeds ranged from 85 to 125 miles per hour. The results showed that even the most severe rainrates produced a misalignment in the alpha-vane of only 1 deg away from the airstream direction. Thus for normal rain conditions experienced by landing aircraft no significant deterioration in alpha-vane performance is expected.

  3. 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.

  4. Impact of simulated acid rain on soil microbial community function in Masson pine seedlings

    Directory of Open Access Journals (Sweden)

    Lin Wang

    2014-09-01

    Conclusion: The results obtained indicated that the higher acid load decreased the soil microbial activity and no effects on soil microbial diversity assessed by Biolog of potted Masson pine seedlings. Simulated acid rain also changed the metabolic capability of the soil microbial community.

  5. 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.

  6. Von Krahli teater kolib mõneks ajaks Saksamaale / Rain Tolk

    Index Scriptorium Estoniae

    Tolk, Rain, 1977-

    2006-01-01

    Von Krahli Teatri selle hooaja eelviimane esietendus "Europiraadid" on 17. mail Düsseldorfis, koostöös Saksamaa teatrirühmaga Showcase Beat Le Mot. Eesti poole pealt teevad kaasa Juhan Ulfsak, Taavi Eelmaa, Maarja Jakobson ja üllatusmängijana filmimees Rain Tolk, kes räägib oma suhtumisest teatrisse ja suhetest Von Krahli Teatriga

  7. 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.

  8. Chemical characterization of rain water in a seasonally dry tropical region (Varanasi), India.

    Science.gov (United States)

    Pandey, Jitendra; Singh, Ashima

    2012-05-01

    Rain water samples, covering 44 rain events of 2008 and 52 rain events of 2009, were collected at urban and suburban locations of Varanasi and analyzed for pH, conductivity and for metal and nutrient ions. The pH of rainwater varied between 6.3 and 7.9, with over 70% of samples having alkaline range. Volume weighed mean concentration of ions indicated Ca2+ (11.62- 41.60 microeq l(-1)) to be the most dominant species followed by SO4(2-) (4.7-25.2 microeq I(-1)), Na+ (1.60-10.25 microeq l(-1)), Mg2+ (0.22-7.21 microeq I(-1)), (NO3(-) (0.73-4.02 microeq l(-1)), K+(0.50-3.70 microeq l(-1)) and PO4(3-) (0.02-0.97 microeq l(-1)) respectively. Among the heavy metals, Cr (12.60 to 44.60 microg l(-1)), Zn (4.25 to 34.55 microg l(-1)) and Mn (10.62 to 28.40 microg l(-1)) were found to be the dominant component of rain water. The varimax rotation of PCA results extracted four major factors namely urban-industrial emission, crustal aerosols, wind transport and biomass burning accounting for 80% of the total variance. The study has relevance in establishing cause-effect relationships for terrestrial as well as for aquatic ecosystems.

  9. Determination of stable and radioactive isotopes in rain water in Sahel in 1975 and 1976

    International Nuclear Information System (INIS)

    Baudet, J.; Abi, B.

    1979-01-01

    The problem of desertification in Africa incites to materialize the circuit of the water vapour between its main source, the Gulf of Guinea, and its precipitation site. Some rainwater samples have been collected in Ouagadougou in 1975 and 1976 during the rainy season. The dosage of the stable isotopes D and O 18 and radioactive isotope T shows that in 1975, a year with a general rain deficit, the rain was formed in a continental air mass. On the contrary, in 1976, a year with excess rain, the rain was formed in a maritime air mass. A study of the wind flows at 600, 900, 1500 and 2100 m shows that in 1975 the monsoon penetration is limited to the bottom of the Gulf of Guinea facing Cameroons, while in 1976 it entered the African Continent through the whole Gulf Coast, from Senegal to Cameroons. In 1976, the monsoon went up in latitude 3 0 to 5 0 more to the north than in 1975 [fr

  10. No Rain, No Food. How Nuclear Techniques can Support Agriculture in Dry Conditions

    International Nuclear Information System (INIS)

    Potterton, Louise

    2011-01-01

    The IAEA through its Research and Technical Cooperation Programmes has implemented 30 water conservation projects in rain-fed agriculture in IAEA Member States in Asia, Africa and Latin America. These projects focus on practises such as minimum tillage, crop residue retention and crop rotation.

  11. Should we be worried about the green paradox? Announcement effects of the Acid Rain Program

    NARCIS (Netherlands)

    Maria, di C.; Lange, Ian; Werf, van der E.

    2014-01-01

    This paper presents the first empirical test of the green paradox hypothesis, according to which well-intended but imperfectly implemented environmental policies may lead to detrimental outcomes due to supply side responses. We use the introduction of the Acid Rain Program in the U.S. as a case

  12. Trends in Pinus ponderosa foliar pigment concentration due to chronic exposure of ozone and acid rain

    International Nuclear Information System (INIS)

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

    1991-01-01

    To determine the effects of ozone and acid rain on mature Ponderosa pine trees, Lawrence Livermore National Lab. has collaborated with University of California Berkeley, University of California Davis, California State University Chico, and the US Forest Service at the latter's Chico Tree Improvement Center. Foliar tissue from mature grafted scions of Pinus ponderosa were exposed to two times ambient ozone for ten months and to acid rain (3.0 pH) weekly for 10 weeks using branch exposure chambers. Pigment extracts were analyzed spectrophotometrically for concentrations of chlorophylls a and b, and carotenoid pigments, at 662 nm, 644 nm, and 470 nm, respectively. Pigment concentrations were expressed on a surface area basis. Preliminary results revealed that chlorophyll a showed a downward trend due to the ozone treatment. Acid rain caused no effects on these three pigments, however, chlorophyll b showed an upward trend due to the interaction of ozone and acid rain. The carotenoid pigments showed no changes due to the treatments either singly, or in combination

  13. 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).

  14. 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:

  15. Analysis of historical rainfall data and associated risks on rain-fed tef ...

    African Journals Online (AJOL)

    The central theme for this paper is studying the rainfall behavior over the past six decades in relation to the major rainfall induced risks for the rain-fed “tef” production system using 59 years of rainfall data. Risk of dry spell during germination and flowering is computed whereas crop water requirement satisfaction index is ...

  16. Effects of experimental snowmelt and rain on dispersal of six plant species

    NARCIS (Netherlands)

    Sarneel, J. M.

    2016-01-01

    Water flows affect dispersal of propagules of many plant species, and rivers and streams are therefore very important dispersal vectors. However, small water flows such as trough rain and snowmelt are much more common, but their effects on dispersal are barely studied. The importance of this form of

  17. Edge effect on palm diversity in rain forest fragments in western Ecuador

    DEFF Research Database (Denmark)

    Baez, S.; Balslev, Henrik

    2007-01-01

    to be idiosyncratic and to depend on the level of disturbance at edges. This paper explores how variation in forest structure at the edges of two old-growth forest fragments in a tropical rain forest in western Ecuador affects palms of different species, life-forms, and size classes. We investigate (1) how edge...

  18. Radar Derived Spatial Statistics of Summer Rain. Volume 2; Data Reduction and Analysis

    Science.gov (United States)

    Konrad, T. G.; Kropfli, R. A.

    1975-01-01

    Data reduction and analysis procedures are discussed along with the physical and statistical descriptors used. The statistical modeling techniques are outlined and examples of the derived statistical characterization of rain cells in terms of the several physical descriptors are presented. Recommendations concerning analyses which can be pursued using the data base collected during the experiment are included.

  19. Effect of simulated sulfuric acid rain on yield, growth and foliar injury of several crops

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J J; Neely, G E; Perrigan, S C; Grothaus, L C

    1981-01-01

    This study was designed to reveal patterns of response of major United States crops to sulfuric acid rain. Potted plants were grown in field chambers and exposed to simulated sulfuric acid rain (pH 3.0, 3.5 or 4.0) or to a control rain (pH 5.6). At harvest, the weights of the marketable portion, total aboveground portion and roots were determined for 28 crops. Of these, marketable yield production was inhibited for 5 crops (radish, beet, carrot, mustard greens, broccoli), stimulated for 6 crops (tomato, green pepper, strawberry, alfalfa, orchardgrass, timothy), and ambiguously affected for 1 crop (potato). In addition, stem and leaf production of sweet corn was stimulated. Visible injury of tomatoes might have decreased their marketabiity. No statistically significant effects on yield were observed for the other 15 crops. The results suggest that the likelihood of yield being affected by acid depends on the part of the plant utilized, as well as on species. Effects on the aboveground portion of crops and on roots are also presented. Plants were regularly examined for foliar injury associated with acid rain. Of the 35 cultivars examined, the foliage of 31 was injured at pH 3.0, 28 at pH 3.5, and 5 at pH 4.0. Foliar injury was not generally related to effects on yield. However, foliar injury of Swiss chard, mustard greens and spinach was severe enough to adversely affect marketability.

  20. Rapid determination of radioactive general β in the rain and snow

    International Nuclear Information System (INIS)

    Li Shuqing; Jiao Shufeng

    1992-01-01

    Deposit filtration has been successfully applied to the determination of radioactive general β in the rain and snow. This method is more direct and rapid than evaporation, and more efficient. The method has been widely used in the emergency monitoring of nuclear pollution

  1. Microwave Remote Sensing of Ocean Surface Wind Speed and Rain Rates over Tropical Storms

    Science.gov (United States)

    Swift, C. T.; Dehority, D. C.; Black, P. G.; Chien, J. Z.

    1984-01-01

    The value of using narrowly spaced frequencies within a microwave band to measure wind speeds and rain rates over tropical storms with radiometers is reviewed. The technique focuses on results obtained in the overflights of Hurricane Allen during 5 and 8 of August, 1980.

  2. 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.

  3. Raindrop size distribution and radar reflectivity-rain rate relationships for radar hydrology

    NARCIS (Netherlands)

    Uijlenhoet, R.

    2001-01-01

    The conversion of the radar reflectivity factor Z (mm6m-3) to rain rate R (mm h-1) is a crucial step in the hydrological application of weather radar measurements. It has been common practice for over 50 years now to take for this conversion a simple power law relationship between Z and R. It is the

  4. Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

    NARCIS (Netherlands)

    Klaassen, W.

    2001-01-01

    Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules

  5. Tropical rain-forest matrix quality affects bat assemblage structure in secondary forest patches

    NARCIS (Netherlands)

    Vleut, I.; Levy-Tacher, I.; Galindo-Gonzalez, J.; Boer, de W.F.; Ramirez-Marcial, N.

    2012-01-01

    We studied Phyllostomidae bat assemblage structure in patches of secondary forest dominated by the pioneer tree Ochroma pyramidale, largely (.85%) or partially (,35%) surrounded by a matrix of tropical rain forest, to test 3 hypotheses: the highest bat diversity and richness is observed in the

  6. Investigating Wind-Driven Rain Intrusion in Walls with the CARWASh

    Science.gov (United States)

    C.R. Boardman; Samuel V. Glass

    2013-01-01

    Wind-driven rain provides the primary external moisture load for exterior walls.Water absorption by the cladding, runoff, and penetration through the cladding or at details determine how a wall system performs. In this paper we describe a new laboratory facility that can create controlled outdoor and indoor conditions and use it to investigate the water...

  7. Development of summer monsoon and onset of continuous rains over central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    rains happening during the last phase of monsoon development as a consequence of and after (2-5 weeks) the establishment of monsoon circulation or monsoon front. Summer monsoon front, as the term 'monsoon' originally meant, is to be delineated from...

  8. Atmospheric pollutants in fog and rain events at the northwestern mountains of the Iberian Peninsula

    International Nuclear Information System (INIS)

    Fernández-González, Ricardo; Yebra-Pimentel, Iria; Martínez-Carballo, Elena; Simal-Gándara, Jesús; Pontevedra-Pombal, Xabier

    2014-01-01

    Atmospheric polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) and exist in gas and particle phases, as well as dissolved or suspended in precipitation (fog or rain). While the hydrosphere is the main reservoir for PAHs, the atmosphere serves as the primary route for global transport of PCBs. In this study, fog and rain samples were collected during fourteen events from September 2011 to April 2012 in the Xistral Mountains, a remote range in the NW Iberian Peninsula. PAH compounds [especially of low molecular weight (LMW)] were universally found, but mainly in the fog-water samples. The total PAH concentration in fog-water ranged from non-detected to 216 ng · L −1 (mean of 45 ng · L −1 ), and was much higher in fall than in winter. Total PAH levels in the rain and fog events varied from non-detected to 1272 and 33 ng · L −1 for, respectively, LMW and high molecular weight (HMW) PAHs. Diagnostic ratio analysis (LMW PAHs/HMW PAHs) suggested that petroleum combustion was the dominant contributor to PAHs in the area. Total PCB levels in the rain and fog events varied from non-detected to 305 and 91 ng · L −1 for, respectively, PCBs with 2–3 Cl atoms and 5–10 Cl atoms. PCBs, especially those with 5–10 Cl atoms, were found linked to rain events. The occurrence of the most volatile PCBs, PCBs with 2–3 Cl atoms, is related to wind transport from far away sources, whereas the occurrence of PCBs with 5–10 Cl atoms seems to be related with the increase of its deposition during rainfall at the end of summer and fall. The movement of this fraction of PCBs is facilitated by its binding to air-suspended particles, whose concentrations usually show an increase as the result of a prolonged period of drought in summer. - Highlights: • There is no work about both PAHs and PCBs in fog-rain events. • None of the existing works is about the case of the northwestern mountains of the Iberian

  9. Atmospheric pollutants in fog and rain events at the northwestern mountains of the Iberian Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-González, Ricardo; Yebra-Pimentel, Iria; Martínez-Carballo, Elena [Nutrition and Bromatology Group, Analytical and Food Chemistry Department, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, E32004 Ourense (Spain); Simal-Gándara, Jesús, E-mail: jsimal@uvigo.es [Nutrition and Bromatology Group, Analytical and Food Chemistry Department, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, E32004 Ourense (Spain); Pontevedra-Pombal, Xabier, E-mail: xabier.pombal@usc.es [Soil Science and Agricultural Chemistry Department, Faculty of Biology, University of Santiago de Compostela, Santiago Campus, E15782 Santiago de Compostela (Spain)

    2014-11-01

    Atmospheric polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) and exist in gas and particle phases, as well as dissolved or suspended in precipitation (fog or rain). While the hydrosphere is the main reservoir for PAHs, the atmosphere serves as the primary route for global transport of PCBs. In this study, fog and rain samples were collected during fourteen events from September 2011 to April 2012 in the Xistral Mountains, a remote range in the NW Iberian Peninsula. PAH compounds [especially of low molecular weight (LMW)] were universally found, but mainly in the fog-water samples. The total PAH concentration in fog-water ranged from non-detected to 216 ng · L{sup −1} (mean of 45 ng · L{sup −1}), and was much higher in fall than in winter. Total PAH levels in the rain and fog events varied from non-detected to 1272 and 33 ng · L{sup −1} for, respectively, LMW and high molecular weight (HMW) PAHs. Diagnostic ratio analysis (LMW PAHs/HMW PAHs) suggested that petroleum combustion was the dominant contributor to PAHs in the area. Total PCB levels in the rain and fog events varied from non-detected to 305 and 91 ng · L{sup −1} for, respectively, PCBs with 2–3 Cl atoms and 5–10 Cl atoms. PCBs, especially those with 5–10 Cl atoms, were found linked to rain events. The occurrence of the most volatile PCBs, PCBs with 2–3 Cl atoms, is related to wind transport from far away sources, whereas the occurrence of PCBs with 5–10 Cl atoms seems to be related with the increase of its deposition during rainfall at the end of summer and fall. The movement of this fraction of PCBs is facilitated by its binding to air-suspended particles, whose concentrations usually show an increase as the result of a prolonged period of drought in summer. - Highlights: • There is no work about both PAHs and PCBs in fog-rain events. • None of the existing works is about the case of the northwestern mountains

  10. 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

  11. Dynamics and sources of pharmaceutically active compounds in a coastal Mediterranean river during heavy rains.

    Science.gov (United States)

    Reoyo-Prats, Brice; Aubert, Dominique; Sellier, Amélie; Roig, Benoit; Palacios, Carmen

    2018-03-01

    Concentrations of pharmaceutically active compounds (PACs) in freshwater systems depend on numerous factors such as land use and hydrometeorological conditions. In the Mediterranean, heavy rain events are of particular importance as they highly influence the concentration of micropollutants found in freshwater and are a source of recurrent first foul flushes due to combined sewer overflows (CSOs). In this study, we seek to assess the dynamics of pharmaceuticals during storm events in coastal Mediterranean rivers at a fine scale and to determine their contribution to multicontamination phenomena owing to CSOs. Our results showed that, while dissolved PACs followed the same trend as other contaminants, i.e., they increased significantly during CSOs, PACs in the total fraction did not peak yet maintained their already high concentrations for slightly longer due to their release via CSOs. Pharmaceutical concentrations for both the dissolved and the total fraction were dramatically diluted during the peak river flow. A fine-scale follow-up of PACs dynamics in the total fraction, including the differentiation of sewer overflows from both the right and left river banks, as well as the analyses of a large amount of PACs molecules, allowed us to clearly identify their major sources. While domestic inputs were dominated by nicotine and caffeine, the use of gadolinium (an MRI contrast agent) as a marker, attributed the main source of medical drugs such as tramadol, ibuprofen, and diclofenac to the major public hospital of the region. Thus, identifying major sources of PACs and implementing adapted water treatments directly at those sources would be the most cost-efficient alternative to cope with pharmaceutical drugs in coastal Mediterranean aquatic environments. Moreover, PACs behavior differed depending on the molecules considered and the source of these molecules, but we could not establish a direct link between their behavior and their chemical or physical properties. Our

  12. Landsliding and flooding event triggered by heavy rains in the Rize region

    Science.gov (United States)

    Yalcin, Ali; Kavurmaci, M. Murat

    2013-04-01

    Rize province has been significantly damaged by frequent landslides and floods which are caused by severe rainfalls and result in many casualties. The area is prone to landslides because of the climate conditions, geologic, and land cover characteristics of the region. The most recent landslide occurred on August 26, 2010 in Gundogdu town. The landslides have caused large numbers of casualties and huge economic losses in the region. Thirteen people died, twenty houses collapsed, more than a hundred houses damaged, and one hundred fifty vehicles were damaged in the Gundogdu landslide. Flood event is often seen in the region of Rize, due to continuous rainfall. Floods cause huge loss of life and property in this region. Rainfall is the most frequent landslide-triggering factor in East Black Sea region, Turkey, especially Rize region. Rize is the rainiest city of Turkey. Total annual precipitation is over 2300 mm, and precipitation is equally distributed in each month. However, in August 26, 166.5 mm precipitation rained within 24 hours in the region and this rainstorm caused great damage. The intensity rainfall periods were become as an indicator of landslide activity. It is very important that the presence of suitable lithologic units for occurring landslides. There are appropriate materials to contributed constitution of landslides in the study area; completely weathered dacite. In addition, intensity land cover types as tea plantations have been blocked surface flows and rainfall is able to quickly penetrate into the soil through open tension cracks that appear in the landslide head and in stretching zones. According to the results of the analysis, the study area has been overlaid tea garden 70 % percentage approximately. Furthermore, the landslide risks have increased by devastation of land cover in this region. In this region, over-steepened slopes, slope saturation in areas of heavy rainfall, and removal of slope vegetation can also increase landslide potential

  13. Evaluation of Satellite Precipitation Products with Rain Gauge Data at Different Scales: Implications for Hydrological Applications

    Directory of Open Access Journals (Sweden)

    Ruifang Guo

    2016-07-01

    Full Text Available Rain gauge and satellite-retrieved data have been widely used in basin-scale hydrological applications. While rain gauges provide accurate measurements that are generally unevenly distributed in space, satellites offer spatially regular observations and common error prone retrieval. Comparative evaluation of gauge-based and satellite-based data is necessary in hydrological studies, as precipitation is the most important input in basin-scale water balance. This study uses quality-controlled rain gauge data and prevailing satellite products (Tropical Rainfall Measuring Mission (TRMM 3B43, 3B42 and 3B42RT to examine the consistency and discrepancies between them at different scales. Rain gauges and TRMM products were available in the Poyang Lake Basin, China, from 1998 to 2007 (3B42RT: 2000–2007. Our results show that the performance of TRMM products generally increases with increasing spatial scale. At both the monthly and annual scales, the accuracy is highest for TRMM 3B43, with 3B42 second and 3B42RT third. TRMM products generally overestimate precipitation because of a high frequency and degree of overestimation in light and moderate rain cases. At the daily scale, the accuracy is relatively low between TRMM 3B42 and 3B42RT. Meanwhile, the performances of TRMM 3B42 and 3B42RT are highly variable in different seasons. At both the basin and pixel scales, TRMM 3B43 and 3B42 exhibit significant discrepancies from July to September, performing worst in September. For TRMM 3B42RT, all statistical indices fluctuate and are low throughout the year, performing worst in July at the pixel scale and January at the basin scale. Furthermore, the spatial distributions of the statistical indices of TRMM 3B43 and 3B42 performed well, while TRMM 3B42RT displayed a poor performance.

  14. Standard test method to determine the performance of tiled roofs to wind-driven rain

    Directory of Open Access Journals (Sweden)

    Sánchez de Rojas, M. I.

    2008-09-01

    Full Text Available The extent to which roof coverings can resist water penetration from the combination of wind and rain, commonly referred to as wind driven rain, is important for the design of roofs. A new project of European Standard prEN 15601 (1 specifies a method of test to determine the performance of the roof covering against wind driven rain. The combined action of wind and rain varies considerably with geographical location of a building and the associated differences in the rain and wind climate. Three windrain conditions and one deluge condition covering Northern Europe Coastal, Central Europe and Southern Europe are specified in the project standard, each subdivided into four wind-speeds and rainfall rates to be applied to the test. The project does not contain information on the level of acceptable performance.Para el diseño de los tejados es importante determinar el punto hasta el cual éstos pueden resistirse a la penetración de agua causada por la combinación de viento y lluvia. Un nuevo proyecto de Norma Europeo prEN 15601 (1 especifica un método de ensayo para determinar el comportamiento del tejado frente a la combinación de viento y lluvia. La acción combinada de viento y lluvia varía considerablemente con la situación geográfica de un edificio y las diferencias asociadas al clima de la lluvia y del viento. El proyecto de norma especifica las condiciones de viento y lluvia y una condición de diluvio para cada una de las tres zonas de Europa: Europa del Norte y Costera, Europa Central y Europa del Sur, cada una subdividida en cuatro condiciones de velocidades de viento y caudal de lluvia para ser aplicadas en los ensayos. El proyecto no contiene la información sobre condiciones aceptables.

  15. Climate change as a confounding factor in reversibility of acidification: RAIN and CLIMEX projects

    Directory of Open Access Journals (Sweden)

    R. F. Wright

    2001-01-01

    Full Text Available The RAIN and CLIMEX experiments at Risdalsheia, southernmost Norway, together cover 17 years (1984-2000 of whole-catchment manipulation of acid deposition and climate. A 1200 m2 roof placed over the forest canopy at KIM catchment excluded about 80% of ambient acid deposition; clean rain was sprinkled under the roof. A climate change treatment (3.7°C increase in air temperature and increase in air carbon dioxide concentrations to 560 ppmv was superimposed on the clean rain treatment for four years (1995-1998. Sea-salt inputs and temperature are climate-related factors that influence water chemistry and can confound long-term trends caused by changes in deposition of sulphur and nitrogen. The RAIN and CLIMEX experiments at Risdalsheia provided direct experimental data that allow quantitative assessment of these factors. Run-off chemistry responded rapidly to the decreased acid deposition. Sulphate concentrations decreased by 50% within three years; nitrate and ammonium concentrations decreased to new steady-state levels within the first year. Acid neutralising capacity increased and hydrogen ion and inorganic aluminium decreased. Similar recovery from acidification was also observed at the reference catchment, ROLF, in response to the general 50% reduction in sulphate deposition over southern Norway in the late 1980s and 1990s. Variations in sea-salt deposition caused large variations in run-off chemistry at the reference catchment ROLF and the year-to-year noise in acid neutralising capacity was as large as the overall trend over the period. These variations were absent at KIM catchment because the sea-salt inputs were held constant over the entire 17 years of the clean rain treatment. The climate change experiment at KIM catchment resulted in increased leaching of inorganic nitrogen, probably due to increased mineralisation and nitrification rates in the soils. Keywords: acid deposition, global change, water, soil, catchment, experiment, Norway.

  16. Antioxidant response of soybean seedlings to joint stress of lanthanum and acid rain.

    Science.gov (United States)

    Liang, Chanjuan; Wang, Weimin

    2013-11-01

    Excess of rare earth elements in soil can be a serious environmental stress on plants, in particular when acid rain coexists. To understand how such a stress affects plants, we studied antioxidant response of soybean leaves and roots exposed to lanthanum (0.06, 0.18, and 0.85 mmol L(-1)) under acid rain conditions (pH 4.5 and 3.0). We found that low concentration of La3+ (0.06 mmol L(-1)) did not affect the activity of antioxidant enzymes (catalase and peroxidase) whereas high concentration of La3+ (≥0.18 mmol L(-1)) did. Compared to treatment with acid rain (pH 4.5 and pH 3.0) or La3+ alone, joint stress of La3+ and acid rain affected more severely the activity of catalase and peroxidase, and induced more H2O2 accumulation and lipid peroxidation. When treated with high level of La3+ (0.85 mmol L(-1)) alone or with acid rain (pH 4.5 and 3.0), roots were more affected than leaves regarding the inhibition of antioxidant enzymes, physiological function, and growth. The severity of oxidative damage and inhibition of growth caused by the joint stress associated positively with La3+ concentration and soil acidity. These results will help us understand plant response to joint stress, recognize the adverse environmental impact of rare earth elements in acidic soil, and develop measures to eliminate damage caused by such joint stress.

  17. Biosignatures of Kerala red rain cells: Implications in understanding their origin

    Science.gov (United States)

    Gangappa, R.; Thomas, M.; Hogg, S.

    2013-09-01

    The red rain that fell over Kerala, southern India (2001-2012) was characterised by the red pigmented particles. Earlier proposal claiming that these are known algal bloom blown from trees (Sampath et al, 2001; DiGregorio, 2007) has been studied by us and disproved. Also, further investigation reporting their extraordinary properties including a suggestion that they lack DNA (Louis and Kumar 2003; 2006; 2008) has been invalidated (Gangappa and Hogg, 2013). However, their claim regarding the growth and replication of these cells at 300ºC needs more investigation if it is to gain acceptance. Current study provide evidences regarding the biological properties of Kerala red rain cells to gain insights into environmental conditions from which they may have originated. Combined with various research strategies and high resolution instruments, we have demonstrated the following interesting properties of Kerala red rain cells: (1) unusually thick external envelope enclosing the central core; (2)stability of red pigment at temperatures about 100ºC and pH variations; (3) absence of eukaryotic ultrastructures; (4) possible replication at 121ºC with nanostructures (possible daughter cells) having similar morphological features inside the large mother cells at such high temperature. They contain high percentage of carbon, iron, silicon and aluminum and often enclosed in a silicon rich biofilms. Further investigation shows that the positive detection of DNA in these cells was possible only after the complete removal of red pigment, thereby providing an explanation for the negative outcome of earlier studies in this regard. Moreover, evidences are shown to support that these cells contain high amounts of UV absorbing compounds, porphyrin complexes and possible scytonemin. Kerala red rain cells may prove to be polyextermophiles belonging to prokaryotes and may have possibly originated from the environment containing above mentioned chemical elements, high energy UV exposure and

  18. 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.

  19. Compliance and the Acid Rain Program : Discussion paper C3-03

    International Nuclear Information System (INIS)

    Sandor, K.

    2002-01-01

    This paper presents the history as well as the implementation and development of the Acid Rain Program and examines whether it was successful in meeting environmental and regulatory goals that led to its enactment. An overview of regulatory policies that influenced sulphur dioxide (SO 2 ) emissions were also presented, along with a discussion regarding emission trends before and after implementation of these policies. The Clean Air Act (CAA) was one of the initial pieces of legislation of the Environmental Protection Agency which was formed in 1970. The CAA was amended in 1990 to provide foundation for the Acid Rain Program. The goal was to reduce acid rain by lowering SO 2 emissions 10 million tons below their 1980 levels to 8.95 million tons by 2010. Innovative emissions cap and trade programs were established to achieve this goal. The first phase of the Acid Rain Program began in 1995 and included 110 of the dirtiest plants emitting SO 2 in the United States. The second phase began in 2000 and included 2,262 operating units. Under the Acid Rain Program, plants have the choice of using technology, previously-implemented controls, retiring plants, and allowances to comply. Many plants are choosing to use more than one of these compliance methods. This paper also discussed the issue of considering emissions trading as a potential component of any future Canadian regulatory policy for greenhouse gases. It was noted that emissions trading provides companies the flexibility to decide how to meet their emissions, or they can pay others to reduce emissions for them. The experience of other jurisdictions were presented in order to effectively design and implement an emissions trading program for greenhouse gases. 16 refs., 1 tab., 8 figs

  20. 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.