No description available.

The isotopic composition of ozone depleting methyl halides may provide valuable information on the sources and sinks of these compounds. However, so far mostly stable carbon isotope analysis of methyl chloride and methyl bromide (CH3Br) has been attempted. Especially halogen isotope analysis has been hindered by the challenge to obtain sufficiently large amounts of methyl halides to meet the detection limits of existing isotope analytical methods. The purpose of this doctoral thesis was to develop both a high-volume cryogenic collection system for methyl bromide (Article II) and an analytical technique being able to analyze the sampled amounts of CH3Br for its Br isotopic composition, which was accomplished by using gas chromatography multiple-collector inductively-coupled plasma mass spectrometry (Article I). These methods were applied in the field campaign from which we report the first bromine isotopic values of CH3Br in the atmosphere (Article III), being in the range of -0.47 to + 1.75 ‰ vs. SMOB (Standard Mean Ocean Bromide). A laboratory study on pectin and halophyte plant material (Article IV) gave an insight in Br isotope composition of abiotically formed CH3Br which may be a main source to the atmospheric budget. These plant experiments yielded δ81Br values of 0 to -2 ‰ SMOB. Atmospheric CH3Br and this potential source showed partly distinct δ81Br ranges and demonstrate the potential of Br isotopes for source apportionment. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Accepted. Paper 3: Submited. Paper 4: Manuscript.</p>

Polar Stratospheric Clouds (PSCs) play a key role for ozone depletion in the polar stratosphere. Its magnitude depends on the type of PSC and its lifetime and extent. This thesis presents PSC observations conducted with the Esrange lidar and the space-borne CALIPSO lidar. PSCs are separated into three types according to their optical properties. The occurrence rate of the different types which are often observed simultaneously as well as their interaction and connection is not well understood. To better understand the processes that govern PSC formation, observations need to be combined with a detailed view of the atmospheric background in which PSCs develop, exist, and are transformed from one type to another. This thesis introduces a new channel of the Esrange lidar for temperature profiling at heights below 35 km. The design of this channel and first temperature measurements within PSCs and cirrus clouds are presented. This is an important step since the majority of PSC-related literature extracts temperatures within PSCs from reanalysis data. In contrast to ground–based measurements space–borne lidar does not rely on cloud–free conditions. Hence, it provides an unprecedented opportunity for studying the connection between PSCs and the underlying synoptic–scale conditions which manifest as tropospheric clouds. This thesis shows that most of the PSCs observed in the Arctic during winter 2007/08 occurred in connection with tropospheric clouds. A combined analysis of ground-based and space-borne lidar observation of PSCs in combination with microphysical modeling can improve our understanding of PSC formation. A first case study of this approach shows how a PSC that was formed by synoptic-scale processes is transformed into another type while passing the Scandinavian mountains. Today a variety of classification schemes provides inconsistent information on PSC properties and types. This thesis suggests a unified classification scheme for lidar measurements of PSCs. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Submitted. </p><p> </p>

I kommunala avloppsreningsverk renas det inkommande avloppsvattnet för att förhindra övergödning och andra olägenheter i våra vattendrag. Reningsprocessen i konventionella avloppsreningsverk består av tre steg, mekanisk, biologisk och kemisk rening. Reningen är designad för att avskilja partiklar, organiskt material och näringsämnena kväve och fosfor från vattnet. Från reningsprocessen uppstår ett avloppsslam som restprodukt. Utöver de ämnen som avloppsreningsverk är designade att avskilja fastläggs även andra, oönskade, ämnen i avloppsslammet. Sådana oönskade ämnen kan vara patogener, metaller och toxiska föreningar som PCB och PAH. Mixen av näringsämnen och potentiellt toxiska ämnen försvårar en användning av slammet. Det är sedan 2005 inte tillåtet att deponera organiskt material vilket innebär att producenter av avloppsslam behöver hitta en avsättningsmöjlighet för det slam som produceras. Ett vanligt användningsområde för slam i Sverige är att använda det till sluttäckning av deponier. Det slam som produceras i Tierps kommun komposteras idag och används till sluttäckning av en deponi. Arbetet med sluttäckningen är snart färdigställt och därefter är det inte bestämt vad de ska göra med slammet. Syftet med det här examensarbetet var att ta fram ett beslutsunderlag för möjliga användningsområden för slammet som produceras i Tierps kommun. Utöver att hitta möjliga användningsområden har även olika behandlingsmetoder för slam utvärderats med avseende på emissioner av växthusgaser och energibehov. De användningsområden som bedömdes som långsiktigt hållbara var att använda slammet som gödsel på åkermark eller att göra anläggningsjord av det. För att få avsättning för de dryga 7000 ton slam som producerades i Tierps kommun under 2016 till åkermark behöver det spridas på cirka 2300 hektar för att inte överskrida gällande gränsvärden med avseende på max tillförsel av koppar. Lagring var den behandlingsmetod gav störst utsläpp av växthusgaser, 1950 ton CO2- ekvivalenter år-1 . Kompostering gav näst störst utsläpp med 200 ton CO2-ekv år-1 . Torkning genererade inga direkta emissioner av växthusgaser men har störst energibehov, 5900 MWh år-1 . Energibehovet för rötning var näst störst och uppgick till 980 MWh år-1 men den rötgas som producerades hade ett energivärde på ca 2240 MWh år-1. För att få en fullständig bild av klimatpåverkan som de olika användningsområdena och behandlingsmetoderna ger upphov till behövs en expansion av det system som studerats i denna studie. Rekommendationen från denna studie är att fortsätta kompostera slammet och använda det till anläggningsjord eller jordförbättringsmedel.

Acting as a hydrological link between the terrestrial landscape and the larger downstream river network, channel heads and their immediate headwaters are essential geomorphological features in our landscape. Not only due to their ability to transport water and sediment and cycling of nutrients, but as an important component for ecosystem productivity and aquatic habitats. Yet, many of our low order streams remain poorly mapped which consequently make development of management policies and protection of them more difficult. A possibility to derive more accurate stream network maps may be achieved by using high resolution digital elevation data (DEM) and hydrological models. A central part in stream network modelling is to develop reliable methods to predict the start of a channel, i.e. the channel heads. Different landscape variables influence the formation and maintenance of channel heads, stressing the need to study their controls in different physiographic regions. Factors influencing channel head formation in the Swedish landscape are yet still relatively unexplored. Investigating the regional and temporal controls on in this landscape are especially interesting since it has a long history of human alterations such as digging of extensive drainage networks, deepening, and straightening of natural stream channels.     The objective of this study is to explore channel head distribution and formation in 12 different forested regions in Sweden using statistical - and GIS analysis. By digitally tracing channel networks upstream using ArcGIS software and a high-resolution DEM (0.5 x 0.5 m), a total of 394 channel heads have been identified and digitized. By calculating the channel heads contributing areas, i.e. the drainage area threshold needed for channels to form, this study have examined regional variations in the size of the contributing area and whether the variability could be attributed to local and average upslope topographic-, soil and hydrological indices. 42 % of the digitized channel heads were identified as being subjected to man-made alterations in some way, remaining were classified as naturally formed channel heads. The contributing area to the channel heads reveled large variability ranging from 0.1 to 58.0 ha for natural to 0.04 to 193.6 ha for more altered channel heads. No evident relationship between size of contributing area and type of Quaternary deposit could be found. Highest median was found in channel heads formed on fine sediment, such as clay, (8.9 ha) however no statistically significant difference in median between different deposits could be confirmed. Channel heads showed only insignificant to weak correlations to the extracted landscape variables, such as the catchment slope and soil moisture index. This could partly be explained by the relatively gentle topography in the investigated regions. The results within this study have highlighted the difficulties to apply traditional methods using topographic indices when delineating and predicting the start of the stream channels in forested and cultivated regions in Sweden. Yet, it has explored the possibility of using high resolution DEM to map and analyze small-scaled landscape features such as channel heads.

Growing industrialization and rising global population have led countries to look for ways to build sustainable energy capabilities. Wind energy has been a promising source of electricity. Offshore and Onshore wind power technology has the ability to tackle big energy and climate challenges, to cause economic growth and create employment. This thesis’ focus will be on offshore technologies. In order to expand globally the installation of these technologies, the installation costs as well as the operation and maintenance (O&amp;M) costs during production stage for them must be reduced and accordingly, the right maintenance strategy should be identified to achieve that. The choice of offshore sites depends heavily on availability, acceptance, funding, availability of the grid and on such factors as depths of sea, weather conditions, logistics, distance from the shore and harbors and soil types are very important economic drivers for project and farm life. These factors also affect the choice of the appropriate maintenance strategy of the wind farm, and it is a great of importance to reduce O&amp;M costs and increase the profits. In this paper, a maintenance strategy appropriate for a specific wind farm located in the Belgian North Sea will be tried to be chosen based on some criteria by the software Decision Analysis Module for Excel (DAME).

SammanfattningDetta examensarbete är utfört på Miljö- och stadsbyggnadsförvaltningen i Haninge kommun och är en utredning om hur dagvatten i den planerade stadsdelen Vegastaden kan hanteras. Vegastaden kommer att innebära 3000 nya bostäder, en ny pendeltågsstation och en ny anslutning till väg 73. Området där Vegastaden kommer att byggas är mycket kuperat och har varierande jordkapacitet. Vissa områden har växlande infiltrationsmöjligheter och består av morän- och hällområden, andra består av täta jordlager av lera med mycket liten genomsläpplighet. Drevviken, som är recipient för dagvattnet i Vegaområdet, är i dagsläget överbelastad med dagvatten så tyngdpunkten har lagts på lokalt omhändertagande av dagvatten. Dammar, trög avledning, våtmark, gröna tak, infiltration och översilningsytor diskuteras i rapporten som även innefattar beräkningar av vattenavrinning, undersökning av infiltrations- och översilningsmöjligheter, fördröjning samt dimensionering av diken och dammar. Examensarbetet ska ge en uppfattning om hur stor del av dagvattnet som kan hanteras genom LOD (lokalt omhändertagande av dagvatten) och ge en idé om hur stora ytor som behövs för fördröjning och rening i dammar. Haninges dagvattenstrategi som antogs i kommunfullmäktige i april 2005 har påverkat utformningen av examensarbetet. Under 1999 och 2000 byggdes en kretsloppsanpassad serviceanläggning, Green Zone, i Umeå som möjligtvis kan ge inspiration till hur dagvattnet i Vegastaden kan hanteras. Samtliga byggnader utformades med gröna tak och minskar avrinningen från hustaken med 50 %. För avrinningsberäkningar och dimensionering av dammar och diken har dataprogrammet Storm Tac använts. Olika scenarier presenteras där det visas hur mycket avrinningen kan reduceras genom olika åtgärder. Då inga åtgärder vidtas beräknas avrinningen till ca 195 506 m 3/år och med rejäla åtgärder i form av gröna tak och infiltrationsytor beräknas avrinningen till 88 137 m 3/år. För att ta hand om det dagvatten som måste ledas bort på grund av att det varken  avdunstar, infiltrerar eller tas upp av växter så har dammar dimensionerats. Beroende på hur stora åtgärder som vidtas för att minska avrinningen varierar dammarnas storlek mellan ca 1 800 m 2och 3 700 m 2. Infiltrationsytor bör läggas där de gör som störst nytta och gröna tak där infiltration en i marken är som sämst. Kan man inte i dagsläget bestämma till hur stor del dagvattnet ska tas omhand lokalt bör förutsättningarna för ett sådant omhändertagande i framtiden göras goda, genom att till exempel bygga taken med en lutning och konstruktion som i framtiden klarar gröna tak och minimera de hårdgjorda ytorna. Då grundvattnet står högt i området är ett dike knappast ett alternativ till bortledning av dagvatten, men däremot skulle en dagvattenkanal i betong klara av att leda bort vatten. Området kan klara sig med endast en damm vad gäller avrinning och rening och den förläggs lämpligast öster om järnvägsspåret där de lägsta punkterna finns. / AbstractThis thesis was carried out at the Environment- and town planning department in the municipality of Haninge and is an inquiry of how stormwater in the planned quarter, Vegastaden, can be managed. Vegastaden will involve 3000 new dwellings, a new commuter train station and a new connection with road 73. Drevviken, which is the recipient of stormwater in the neighbourhood of Vega, is overloaded with stormwater so the focus in this thesis is on local management of stormwater. Ponds, slow off leading, wet lands, green roofs, infiltration and filter strips are discussed in the thesis which even contains calculations of water run off, investigation of infiltration- and filter strips possibilities, slow off leading and dimensioning of swales and ponds. The thesis will give an apprehension of how large volume of the stormwater that can be handled through local handling of stormwater and give an idea of how large areas that will be needed for retardation and treatments in ponds. The stormwater strategy of Haninge was accepted in the municipal council in April 2005 and has influenced the model of this thesis. The area where Vegastaden will be built is very hilly and has varying ground capacity. Some areas have varying infiltration possibilities and consists of moraine and flat rocks, other areas consists of seal earth-layers of clay with minimal permeability. During 1999 and 2000 an ecocycle society service construction, Green Zone was built in Umeå which possibly can give inspiration in how to manage the storm water in Vegastaden. All the buildings were designed with green roofs which reduce run off from the roofs with 50 %. The computer program Storm Tac has been used for run off calculations and dimensioning of ponds and swales. Different scenes are introduced where it shows how much of the run off that can be reduced through different measures. When no measures are taken the run off is calculated to ca 195 506 m 3/year and with great measures in form of green roofs and filter strips the run off is calculated to ca 88 137 m 3/year. To manage the stormwater that has to be led off on account of no evaporation or infiltration ponds have been dimensioned. Depending on the measures taken to reduce the run off, the size of the ponds will vary between ca 800 m 2and 3700 m2. Filter strips should be placed where they do the greatest good and green roofs where the infiltration in the ground is the worst. If there is no way today to decide how much of the storm water that should be managed locally the conditions for such a management in the future should be favoured through for example green roof friendly roof constructions and to minimize the non-permeable surfaces. Because of the high ground water in the area a swale is hardly a good alternative when leading off storm water, but a stormwater canal of concrete should be able to lead off stormwater. The area should manage with only one pond regarding run off and treatment and is suitably placed east of the railway where the lowest parts are.

SummaryThe area of study in this project is in Bolivia, South America. The specific area is theMunicipality of Tiquipaya, situated in Cochabamba valley. Cochabamba valley consists of a gently sloping plain bounded by steep slopes of the Cordillera. The vegetation in the Cordillera is mostly high steppe and high mountain prairie. The average annual precipitation is 600-1000 mm/ year. When it rains in the mountain range the rivers flow down to the valley with high velocity and cause great problems with erosion. In the valley the average annual precipitation is 500 mm/year and the land use is mostly agricultural. Because of the intense agriculture and the rapid population growth, Cochabamba Central Valley suffers a constant shortage of water. Different irrigation systems and groundwater from the aquifer supplies Tiquipaya with water.The aquifer in Tiquipaya is one out of three thick sedimentary bodies in the Central Valley. The aquifer is an alluvial fan delta and the thickness is approximately 500 m. It is recharged through infiltration from the mountain rivers, precipitation on the valley area and by irrigation. The discharge from the aquifer consists of wells and springs. There are 37 flowing springs in Tiquipaya and they have been in use for hundreds of years. During the last 10 years the habitants have noticed a decreasing amount of flow in the springs. This indicates that the groundwater level is sinking. In order to find out whether or not the aquifer reserve is decreasing a water balance is calculated. To estimate the recharge to the aquifer we had access to precipitation data, but we had to estimate the evapotranspiration and the percentage which infiltrates. Concerning the discharge we had access to specific spring data over two areas and a list of registered wells. We know that there are more wells then the ones registered, but we did not know how many and what flow rate they have. Based on the existing data and our assumptions we have estimated a possible discharge for the Tiquipaya area. To get a truthful picture of the reality, we have made three water balances based on different data and variations. The one we find most likely show that the aquifer is decreasing.The aquifer is under a lot of environmental threats. The town of Tiquipaya is situated on the aquifer and the town’s residual water is used as irrigation water without any treatment. Also the river beds, which are very permeable recharge zones, are being used as garbage heaps. Concerning the aquifer the most impending problems are the use of residual water and the garbage handling. To obtain a sustainable development the habitants' residual water and garbage have to be taken care of.As a conclusion we do not think that the actual situation in Tiquipaya is sustainable. The groundwater reserve is decreasing and can not supply enough water for the municipality. If the agriculture stays as intensive as it is today the municipality needs to supplement with water from watersheds outside of the Cochabamba Valley. This would also give the aquifer a chance to restore its reserve. The completion of the Misicuni project will hopefully provide Tiquipaya with the water supplement needed. In order to determine the exact extension and capacity of the aquifer more reliable data is needed. We recommend geophysical tests, drilling and field investigations to obtain this data. / Resumen El área de estudio de este proyecto es la municipalidad de Tiquipaya, situado en el valle central de Cochabamba, Bolivia. El valle central de Cochabamba consta de una llanura suavemente inclinada, limitada por las empinadas montañas de la ordillera. La vegetación en la Cordillera es principalmente estepa alta y pradera de montaña alta . La precipitación media anual es 600-1000 milímetros / año. Cuando llueve en la Cordillera los ríos fluyen al valle con una velocidad muy alta, causando grandes problemas con la erosión. En el valle la precipitación media anual es 500 milímetros / año y el uso de suelo es principalmente agrícola. Debido a la agricultura intensa y el rápido crecimiento de población, el valle central de Cochabamba se ve constantemente afectado por una escasez de agua. Diferentes sistemas de irrigación y agua subterránea del acuífero intentan proporcionar Tiquipaya con el agua. El acuífero en Tiquipaya es uno de tres cuerpos sedimentarios gruesos en el valle central. El acuífero es formada por depósitos aluviales que forman conos y abanicos con un espesor de 500 m. El acuífero es recargado a través de infiltración de los ríos de montaña, de la precipitación sobre el valle y por la irrigación.La descaraga del acuífero consta de pozos y vertientes. Hay 37 vertientes fluyendo en Tiquipaya y han sido usados durante cientos de años. Durante los últimnos 10 años los habitantes ha n notado una disminuación en el flujo de los vertientes. Esto indica que el nivel estático de agua está hundiendo. Para entender si la reserva de acuífero está disminuyendo o no, un balance hídrico es calculado. Para calcular la recarga del acuífero teníamos acceso à los datos de precipitación, pero tuvimos que calcular el evapotranspiración y los porcentajes que se infiltra. Al calcular la descarga teníamos acceso a datos específicos de los vertientes en dos áreas y una lista de pozos registrados. Sabemos que hay más pozos que los en la lista, pero no sabemos cuántos y qué flujo tienen. Basado en los datos existentes y nuestras suposiciones hemos calculado una descarga posible para la área de Tiquipaya. Para conseguir un modelo sincero de la realidad, hemos hecho tres balances de agua basados en diferentes datos y variaciónes. El balance que muestra que el acuífero está disminuyendo es el más probable. Para el acuífero hay muchas amenazas ambientales. El pueblo de Tiquipaya está situado sobre el acuífero y el agua residual del pueblo es usada en la irrigación sin cualquier trato. También las zonas de recarga son muy sensatas y se estan usando los lechos del río como basurales. Con respecto al acuífero de agua subterránea los problemas más inminentes son el uso del agua residual y el manejo de basura. Para obtener un desarrollo sostenible, los problemas de aguas residuales y basura tienen que ser solucionados. Como conclusión no pensamos que la situación actual en Tiquipaya sea sostenible. La reserva de agua subterránea está disminuyendo y no puede proporcionar suficiente agua para la municipalidad. Si la agricultura se queda tan intensiva como es hoy la municipalidad tiene que complementar con agua de aréas fuera del valle de Cochabamba. Esto también daría una oportunidad a la reserva del acuífero de restituirse. La terminación del proyecto de Misicuni posiblemente suministrará Tiquipaya con el suplemento de agua necesitado.Para determinar la extensión exacta y la capacidad del acuífero datos más  confiables son necesitados. Recomendamos pruebas geofísicas, pruebas de bombeo y investigaciones de campo para obtener estos datos.

Incoherent scatter radars are powerful ground based instruments for ionospheric measurements. By analysis of the Doppler shifted backscatter spectrum, containing the signature of electrostatic plasma waves, plasma bulk properties are estimated. Occasionally, the backscattered radar power is enhanced several orders of magnitude above the thermal backscatter level. These enhancements occur during naturally disturbed ionospheric conditions and in ionospheric modi_cation experiments, where a powerful radio wave is incident on the ionospheric plasma. In both of the cases the non-linearity is thought to be turbulence of electrostatic Langmuir waves. The Langmuir turbulence theory and models account for many features of enhanced ionospheric radar backscatter reported on in the literature. During disturbed conditions, with precipitation of auroral electrons, Langmuir turbulence is thought to be driven by a low energy electron beam. Optical and radar observations of naturally enhanced radar backscatter indicate Alfvénic type of aurora during events reported on in the literature. However, contrasting conclusions have been drawn from optical observations. While some reports suggest that enhanced radar backscatter is observed at the edge of auroral structures others suggest that the enhanced backscatter region and auroral precipitation are co-located. Optical imagers with a narrow field of view resolve auroral structures with tens of meters scale size. The cross beam resolution of radars, however, is limited by the width of the radar beam, typically several kilometers wide at auroral altitudes. By using several radar receivers for observations - radar interferometry - the cross beam resolution is increased. Simultaneous observations of enhanced radar backscatter with radar interferometry and narrow field of view optical observations will increase the understanding of the physical processes involved and will make it possible to associate auroral structures with the enhanced radar backscatter. An interferometric radar receiver system has been built and a calibration technique for the system developed. In ionospheric modification experiments, the Langmuir turbulence is driven by a powerful electromagnetic wave incident on the ionosphere and electrons are significantly accelerated. The acceleration of electrons is not yet fully understood. Ionospheric modification experiments and ground based measurements, as reported on herein, contribute to the understa / <p>QC 20130131</p>

No description available.