Aquatic environments contain a great diversity of microorganisms, some of which may be aerosolized and transported long distances through the atmosphere. The bacterium Pseudomonas syringae can be found in aquatic environments and in the atmosphere and may express an ice nucleation protein (bacteria expressing the protein are Ice+ and bacteria not expressing the protein are Ice-). Ice+ bacteria may be involved in cloud formation and precipitation processes due to their ability to freeze water at warmer temperatures. Freshwater aerosolization processes are not well understood, particularly the role the Ice+ phenotype may play. Water samples were collected from Claytor Lake, Virginia, USA and screened for Ice+ P. syringae. Results indicated that between 6% and 15% of Pseudomonas colonies assayed were Ice+. Preliminary phylogenetic analysis of cts (citrate synthase) sequences from strains of P. syringae showed a surprising diversity of phylogenetic subgroups present in the lake. A Collison nebulizer was used to aerosolize an Ice+ and an Ice- strain of P. syringae under artificial laboratory conditions. The aerosolization of P. syringae was not influenced by water temperature between 5° and 30°C. In general, the culturability (viability) of P. syringae in aerosols increased with temperature between 5 and 30°C. The Ice+ strain was aerosolized in greater numbers than the Ice- strain at all temperatures studied, suggesting a possible connection between the Ice+ phenotype and aerosol production. A quantitative empirical assessment of aerosolized droplets was generated using a laboratory flume and high-speed video. Droplet diameter and initial velocity upon leaving the water surface were examined at four wind speeds (3.5, 4.0, 4.5, and 5.0 m/s), and the results showed that droplet diameter and velocity had a gamma distribution and droplet mass flux increased exponentially with wind speed. An estimate of the potential amount of bacteria capable of aerosolizing was made for each wind speed. An interdisciplinary unit for advanced high school students has been developed presenting biological aerosolization and ice nucleation. This interdisciplinary work combines modeling and experimental approaches across biology and engineering interfaces, with the goal of increasing our understanding of microbial aerosols from aquatic environments that may impact our planet's water cycle. / Ph. D.

Large explosive volcanic eruptions inject SO2 into the stratosphere where it is oxidised to sulphate aerosols which reflect sunlight. This causes a reduction in global temperature and precipitation lasting a few years. Here the robust features of this precipitation response are investigated, using superposed epoch analysis that combines results from multiple eruptions. The precipitation response is first analysed using the climate model HadCM3 compared to two gauge based land precipitation datasets. The analysis is then extended to a large suite of state-of-the art climate models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5). This is the first multi-model study focusing on the precipitation response to volcanoes. The large ensemble allows analysis of a short satellite based dataset which includes ocean coverage. Finally the response of major world rivers to eruptions is examined using historical records. Whilst previous studies focus on the response of just a few rivers or global discharge to single eruptions, here the response of 50 major world rivers is averaged across multiple eruptions. Results are applicable in predicting the precipitation response to future eruptions and to geoengineering schemes that seek to counteract global warming through reducing incoming solar radiation. The main model-simulated features of the precipitation response include a significant global drying over both land and ocean, which is dominated by the wet tropical regions, whilst the dry tropical ocean regions get significantly wetter following eruptions. Monsoon rainfall decreases, whilst in response to individual eruptions the Intertropical Convergence Zone shifts away from the hemisphere with the greater concentration of volcanic aerosols. The ocean precipitation response is longer lived than that over land and correlates with near surface air temperature, whilst the land response correlates with aerosol optical depth and a reduction in land-ocean temperature gradient Many of these modelled features are also seen in observational data, including the decrease in global mean and wet tropical regions precipitation over land and the increase of precipitation over dry tropical ocean regions, all of which are significant in the boreal cold season. The land precipitation response features were robust to choice of dataset. Removing the influence of the El Nino Southern Oscillation (ENSO) reduces the magnitude of the volcanic response, as several recent eruptions coincided with El Nino events. However, results generally remain significant after subtraction of ENSO, at least in the cold season. Over ocean, observed results only match model expectations in the cold season, whilst data are noisy in the warm season. Results are too noisy in both seasons to confirm whether a long ocean precipitation response occurs. Spatial patterns of precipitation response agree well between observational datasets, including a decrease in precipitation over most monsoon regions. A positive North Atlantic Oscillation-like precipitation response can be seen in all datasets in boreal winter, but this is not captured by the models. A detection analysis is performed that builds on previous detection studies by focusing specifically on the influence of volcanoes. The influence of volcanism on precipitation is detectable using all three observational datasets in boreal winter, including for the first time in a dataset with ocean coverage, and marginally detectable in summer. However, the models underestimate the size of the winter response, with the discrepancy originating in the wet tropics. Finally, the number of major rivers that undergo a significant change in discharge following eruptions is slightly higher than expected by chance, including decreased flow in the Amazon, Congo, Nile, Orange, Ob and Yenisey. This proportion increases when only large or less humanly influenced basins are considered. Results are clearer when neighbouring basins are combined that undergo the same sign of CMIP5 simulated precipitation response. In this way a significant reduction in flow is detected for northern South American, central African and less robustly for high-latitude Asian rivers, along with a significant increase for southern South American and SW North American rivers, as expected from the model simulated precipitation response.

A land-surface module to couple a meteorological and a hydrologic model is described. lt was implemented and tested in the Leipzig\'s version of GESIMA. Preliminary results of a coupling with NASMO are presented, although this article mainly focuses on the description of the module and its effect on the atmospheric water cycle. One positive impact of the module is that it allows to produce subgrid-scale evapotranspiration in more details and to heterogenize precipitation. This strongly affects soil wetness, cloudiness and the thermal regime of the atmospheric boundary layer. / Ein Bodenmodul zur Kopplung eines meteorologischen mit einem hydrologischen Modell wird vorgestellt. Er wurde implementiert und getestet in der Leipziger Version von GESIMA. Obgleich der Schwerpunkt des Artikels auf der Beschreibung des Moduls und seiner Auswirkung auf den atmosphärischen Wasserkreislauf liegt, werden auch vorläufige Ergebnisse einer Kopplung mit NASMO präsentiert. Ein positiver Effekt des Moduls ist, daß er ermöglicht, detaillierter die subskalige Evapotranspiration zu beschreiben und den Niederschlag zu heterogenisieren. Dies wirkt sich stark auf die Bodenfeuchte, die Bewölkung und das thermische Regime der atmosphärischen Grenzschicht aus.

O presente trabalho investiga a construção de abordagens centradas em temas, dirigidas ao ensino médio, tomando como exemplo a temática da água. A escolha do tema tem sua justificativa apoiada na ampla abordagem que ele proporciona, desde questões ambientais e socioeconômicas, até as possibilidades de revitalizar o potencial da escola em gerar participação. Para a construção da proposta analisamos, inicialmente, dois aspectos que contextualizam um espaço de intervenção, caracterizando, por um lado, a estrutura curricular em que o tema pode ser inserido, a partir da análise de livros didáticos e, por outro, algumas idéias de alunos sobre a questão. Em particular, investigamos a articulação entre os aspectos dos temas tratados e os conceitos físicos a serem construídos. Nesse sentido, propomos a construção de representações de duas naturezas diferentes, denominadas de organização temática e organização conceitual, que, em conjunto, representam o âmbito das escolhas dos percursos temáticos a serem construídos pelos alunos e professores. Como exemplo, desenvolvemos três percursos temáticos, considerando como ponto de partida a questão de uma eventual escassez futura de água e representações do ciclo da água. Analisamos, ainda, o sentido da introdução de uma abordagem complexa para as questões das águas, buscando investigar em que consiste tal abordagem. Dessa forma, além de aprofundar a temática da água, propomos elementos que podem servir de ponto de partida para a construção de propostas temáticas e novas investigações. / The present work investigates the design of thematic approaches to be developed in science classes at High School level. It takes as an example questions and aspects related to the water thematic. The choice is justified by the wide range of possibilities that it provides, including environmental as well as social and economic aspects. In addition, it allows students involvement on social meaningful questions. To a first approximation, it is proposed a characterization of the intervention background conditions, by investigating the curriculum structure in that the theme can be inserted, using for that textbook analyzes. In this same direction, students´ ideas on the subject are also important sources and must be considered. For the designing of the approach, it is proposed the identification and construction of two different conceptual network structures, one referred to thematic organization and the other to physical concepts organization. These structures together represent the ambit of the choices about what teachers and students can decide to study. Each proposition of study or course means a specific interrelation of elements from these two structures, a specific itinerary to be built. As examples, three thematic paths are presented, all considering the question of an eventual future shortage of water and representations of the water cycle. In these examples, it is also analyzed the meaning of introducing complexity approaches, trying to identify its implication. With these contributions, this work pretends to have recognized some meaningful elements to be considered in the design of thematic instructions and also aspects that need to be better investigated about the subject.

<h1>Abstract</h1><p>The work will give the picture of what four- and five-year-olds know about the water cycle in nature and in the society. Is there any difference depending on whether a boy or a girl is answering? The work will as well try to describe a picture of how a pre-school could plan their work on a sustainable society, science, and increased gender equality. To answer these questions the information has been received from interviews with children and by studying pre-school’s local plan. </p><p>   Earlier research on the area of water shows that it is important before working with a new topic to find out what knowledge the children already have, so that the process could be as worthwhile as possible. The proceeding work should be based on children’s previous knowledge of the topic.</p><p>   The research has been done on twelve four- and five-year-old children with the help of individual interviews. The result of the research shows that the children have some knowledge of the words which are important for understanding of the water cycle in nature, but they are not capable of talking about the entirety, as the complete cycle. The water cycle in the society is even more difficult for the children to describe, although there were some children who could explain the function of the water tower. The children do not even show the understanding or knowledge of the words which are included into the concept. The local plan gives a good picture of how the work could be planned in an appropriate way to increase the environmental awareness and equality.</p><p>   To sum up, this work will show a picture of what children know nowadays about the water cycle. Different answers can be received depending on the location of the pre-school. Identical background can lead to similar answers. <strong>If pre-schools have an opportunity to go to the forest often, the children then have the experience from there as well and answer more similar than if the</strong><strong> </strong><strong>opportunity doesn’t exist.</strong> The teacher shall help the children to explore there environment in as simple and interesting way. A well-planned local plan helps the pre-school become as good as possible. The children feel participating if they get attention and praise. </p><p>Key-words: The water cycle, Children's thoughts, Gender, Local plan.</p> / <p> Sammanfattning</p><p>Arbetet ger en bild av vad fyra och femåringar kan om vattnets kretslopp i naturen och i samhället. Är det någon skillnad i svar om det är en pojke eller en flicka som svarat? Det försöker även ge en bild av hur en förskola kan planera för ett hållbart samhälle, naturvetenskap, och ökad jämställdhet. Information för att få svar på dessa frågor har hämtats från barnintervjuer och studie av förskolans lokala verksamhetsplan.                                                                                     </p><p>   Tidigare forskning inom området vatten visar på att det är viktigt att man tar reda på vad barnen har för förkunskaper när ett nytt område startas för att det ska bli så bra som möjligt. Barnens förkunskaper ska vara en grund för det fortsatta arbetet.</p><p>   Studien har genomförts på tolv stycken barn i fyra- fem års åldern i enskilda intervjuer. Resultaten av undersökningen visar på att barnen har kunskap kring en del ord som är viktiga för att förstå vattnets kretslopp i naturen men de kan inte sätta ihop detta till en helhet, ett slutet kretslopp. Vattnets kretslopp i samhället är än svårare för barnen att kunna förklara även om det fanns barn som kunde redogöra för vattentornets funktion. Barnen har sämre förståelse och kunskap om vilka ord som berör vattnets kretslopp. Verksamhetsplanen ger en god bild av hur man kan planera sin verksamhet på ett bra sätt för ökad miljömedvetenhet och jämställdhet.¨</p><p>  Sammanfattningsvis ska detta arbete försöka spegla vad barn kan idag om vattnets kretslopp. Svaren kan skilja sig åt beroende på var någonstans förskolan är placerad. Lika förutsättningar kan leda till liknande svar. Om förskolor har möjlighet att gå till skogen ofta har barnen en erfarenhet därifrån och svarar då mer lika än om möjligheten inte finns. Pedagogen ska hjälpa barnen att kunna utforska sin omgivning på ett enkelt och roligt sätt. En bra och genomtänkt verksamhetsplan hjälper arbetet på förskolan att bli så bra som möjligt. Barnen känner sig delaktiga om de får uppmärksamhet och beröm.</p><p>Nyckelord: Vattnets kretslopp, Barns tankar, Genus, Verksamhetsplan.</p>

<p>Syftet med den här undersökningen är att ta reda på hur experiment kan förändra barns förståelse kring vattnets kretslopp. Det är åtta barn mellan fyra och fem år som har deltagit i undersökningen genom intervjuer, sagoberättande och konstruerat vattnets kretslopp i en glasburk. Förståelsen om vattnets kretslopp var olika från individ till individ, det varierade i svaren från barnen om vatten finns och om det finns vatten överallt på jorden, men alla var inte överens om att det fanns. I den första intervjun var det inte många som visste vad vattnets kretslopp var. En kille förklarade vattnets kretslopp mycket bra genom intervjufrågorna och följdfrågorna jag ställde till honom. I den andra intervjun hade de flesta barnen en helt annan förståelse om vattnets kretslopp. Spontana reflektioner från barnen var att vatten kom ifrån vattenkranen, bäckar, badhuset och från Norge.</p> / <p>The purpose of this survey is to understand how experiments can change children's understanding of circle of water. Eight children between four and five years old have participated in the survey through interviews, storytelling, and have simulated the circle of water in a can of glass. The understanding of the circle of water changes from one person to another, the answer from the children varied about where to find water and if there is water all over the world, but not everyone agreed. In the first interview not everyone agreed on what the circle of water was. In the second interview the children had quite different understandings of the circle of water. Spontaneous reflection from the children was that water emerged from water taps, streams, public swimming pools, and from Norway.</p>

Syftet med den här undersökningen är att ta reda på hur experiment kan förändra barns förståelse kring vattnets kretslopp. Det är åtta barn mellan fyra och fem år som har deltagit i undersökningen genom intervjuer, sagoberättande och konstruerat vattnets kretslopp i en glasburk. Förståelsen om vattnets kretslopp var olika från individ till individ, det varierade i svaren från barnen om vatten finns och om det finns vatten överallt på jorden, men alla var inte överens om att det fanns. I den första intervjun var det inte många som visste vad vattnets kretslopp var. En kille förklarade vattnets kretslopp mycket bra genom intervjufrågorna och följdfrågorna jag ställde till honom. I den andra intervjun hade de flesta barnen en helt annan förståelse om vattnets kretslopp. Spontana reflektioner från barnen var att vatten kom ifrån vattenkranen, bäckar, badhuset och från Norge. / The purpose of this survey is to understand how experiments can change children's understanding of circle of water. Eight children between four and five years old have participated in the survey through interviews, storytelling, and have simulated the circle of water in a can of glass. The understanding of the circle of water changes from one person to another, the answer from the children varied about where to find water and if there is water all over the world, but not everyone agreed. In the first interview not everyone agreed on what the circle of water was. In the second interview the children had quite different understandings of the circle of water. Spontaneous reflection from the children was that water emerged from water taps, streams, public swimming pools, and from Norway.

An analytic boundary layer model for thermal convection with a finite-strength plate and depth-dependent viscosity is developed. The model includes a specific energy balance for the lithosphere and accounts for coupling between the plate and underlying mantle. Multiple solutions are possible with three solution branches representing three distinct modes of thermal convection. One branch corresponds to the classic boundary layer solution for active lid plate tectonics while two new branches represent solutions for sluggish lid convection. The model is compared to numerical simulations with highly temperature dependent viscosity and is able to predict both the type of convection (active, sluggish, or stagnant lid) as well as the presence of single and multiple solution regimes. The existence of multiple solutions suggests that the mode of planetary convection may be history dependent. The dependence of mantle viscosity on temperature and water concentration is found to introduce a strong dynamic feedback with plate tectonics. A dimensionless parameter is defined to quantitatively evaluate the relative strength of this feedback and demonstrates that water and heat transport may be equally important in controlling present-day platemantle dynamics for the Earth. A simple parameterized evolution model illustrates the feedback and agrees well with our analytic results. This suggests that a simple relationship may exist between the rate of change of water concentration and the rate of change of temperature in the mantle. This study concludes by investigating the possibility of a magnetic field dynamo in early solar system planetesimals. The thermal evolution of planetesimals is modeled by considering melting, core formation, and the onset of mantle convection and then employing thermal boundary layer theory for stagnant lid convection (if possible) to determine the cooling rate of the body. We assess the presence, strength and duration of a dynamo for a range of planetesimal sizes and other parameters. We find that a minimum radius of O(500) km is required for a thermally driven dynamo of duration O(10) My. The dependence of the results on model parameters is made explicit through the derivation of an analytic solution. / Earth and Planetary Sciences

The aim of this study is to investigate if pedagogues, by different activities, can increase childrens awareness and curiosity for the ecological water cycle. Further, to identify the thoughts children between three and five years old have about the ecological water cycle. In order to review this, eight children participated in four group activities, and afterwards they were interviewed individually about their thoughts regarding water. The children were aware that water occurs in different aggregation forms, which is important to know when trying to understand the ecological water cycle. The activities were a valuable method to stimulate childrens interest in the ecological water cycle. It was reviled that it is difficult for children to understand the abstract parts in the water cycle, such as water vapor. Most of the children were able to describe a simple variant of the water cycle. / Syftet med detta arbete är att undersöka om pedagogerna genom aktiviteter kan utveckla barnens intresse för vattnets kretslopp samt vilka tankar som barn i tre till femårsålder har om vattnets kretslopp. För att komma fram till resultatet så har 8 barn deltagit i fyra gruppaktiviteter och efter det har de intervjuats enskilt om deras tankar kring vatten. Alla barnen visste att vatten förekommer i olika aggregationsformer. För att förstå processen kring vattnets kretslopp är det viktigt att förstå att vatten förekommer i olika aggregationsformer. De aktiviteter som användes i studien visade sig vara bra aktiviteter för att stimmulera barnens intresse för vattnets kretslopp. Det är svårt för barnen att förstå det abstrakta i kretsloppet, som till exempel vattenånga. Flertalet av barnen kunde redogöra för en enkel variant av vattnets kretslopp.

Syftet med detta arbete var att skapa ett läromedel för undervisning i kemi och fysik. Den huvudsakliga utgångspunkten är tagen i läroplanens centrala innehåll för ämnena kemi och fysik i skolår 4-6. Målet har varit att aktiviteterna som finns beskrivna i läromedlet ska ge en helhetsbild och kombinera teori med praktiska uppgifter. Resultatet av vårt utvecklingsarbete mynnade ut i ett läromedel som består av lärarhandledning med tillhörande elevkompendium. I läromedlet finns praktiska aktiviteter som inte kräver någon specialutrustning eller speciell laborationssal. Aktiviteterna går att utföra i klassrummet med enkla och lättillgängliga vardagsmaterial. Läromedlet är utformat för undervisning på mellanstadiet men går naturligtvis att anpassas till tidigare eller senare år. / The purpose of this essay was to create a teaching aid for education in chemistry and physics. The main starting point is taken from the curriculum's central content for chemistry and physics in grades four through six. The aim was to create a teaching aid that combines theory with practical tasks. The teaching aid consists of a teaching guide with belonging student compendium. The practical activities described do not require any special equipment or laboratory rooms.  They can easily be performed inside the classroom with simple and accessible everyday items. The teaching aid is designed for education in grades four through six, but can of course be adapted for use in lower or higher grades.