Previous studies, such as van der Veen (2012) and White et al. (2017), have demonstrated the potential of using measurement-based cloud data to improve Numerical Weather Prediction (NWP) based cloud forecasts. This can be done through cloud initialization; a process of injecting cloud data after the regular data assimilation in an NWP model. The purpose of this study was to use cloud data from the Mesoscale Analysis system MESAN to investigate cloud initialization in the HARMONIE-AROME model system for improving short-range cloud forecasts. The cloud initialization method that was used was similar to a method used by van der Veen (2012), where specific humidities, temperatures, and hydrometeor concentrations were altered using information on cloud fractions, cloud base heights and cloud top heights. MESAN input data analyses as well as cloud initialization investigations were carried out. MESAN input data analyses revealed significant differences in cloud fractions between MESAN and the background model field in MESAN. Overestimations of cloud fractions in MESAN over sea were caused by satellite data, particularly due to the inclusion of the fractional cloud category. Underestimations of cloud fractions over land were caused by limitations of the synoptic weather (SYNOP) stations in measuring clouds. Furthermore, larger differences between MESAN and SYNOP were found over Sweden and Finland compared to Norway, which may be tied to Norway having mostly manual SYNOP stations, and Sweden and Finland having mostly automatic stations. Shortcomings were found in the investigated cloud initialization method. Such shortcomings involved a limit check on the specific humidity change, the cloud initialization being repeated for an unnecessarily large amount of iterations, and the use of a sub-optimal profile of critical relative humidity. Using a one-dimensional vertical column version of HARMONIE-AROME, named MUSC, to integrate forward in time revealed a large sensitivity to the use of forcing profiles and forcing time scales in MUSC. Alterations made through cloud initialization were found to last over 12 h, with varying effects depending on the investigated height. A reasonably good agreement between MUSC results and results from the three-dimensional version of HARMONIE-AROME was found. Findings in this thesis point at potential to further enhance the HARMONIE-AROME cloud initialization technique. These enhancements concern a revised MESAN cloud product and taking care of some flaws in the cloud initialization method. / I en operationell vädermodell inkluderas olika mätdata, såsom temperatur och atmosfärstryck, i ett regelbundet intervall. Molnighet är inte vanligtvis en del av dessa cykler; istället bildas molnen av modellen utifrån balanser i de andra fysikaliska fälten. Detta projekt gick ut på att direkt införa molnmätningar från väderanalyssystemet MESAN i vädermodellsystemet HARMONIE-AROME genom en metod som kallas molninitialisering. Specifikt förbättringar för korttidsprognoser var av i ntresse. MESAN är ett system vars produkter är en sammanslagning av ett bakgrundsfält från en vädermodellkörning med olika mätdata. I MESAN kommer molndata från tre källor: bakgrundsfältet, satellitdata och synoptisk väderstationsdata (SYNOP-data). Undersökningar av indata till MESAN samt molninitialiseringsmetoden har utförts. Analyser av indata till MESAN visade på överskattningar av moln i satellitdata över hav och underskattningar av moln i SYNOP-data över land. För satellitdatat berodde detta på medtagande av moln på liten skala eller väldigt tunna moln, medan det för SYNOP berodde på begränsningar i mätmetoderna. Det fanns även en skillnad i kvalitet i SYNOP-data i Sverige och Finland gentemot Norge, vilket kan bero på att de flesta mätstationer i Norge är manuella medan de flesta i Sverige och Finland är automatiska. Molninitialiseringsmetoden bestod i att extrahera data om molnbashöjd och molntopphöjd från MESAN, och sedan modifiera fuktighet, temperatur och hydrometeorer (såsom molndroppar och iskristaller) i HARMONIE-AROME utifrån molnens position. Brister i metoden hittades. Initialiseringsprocessen upprepades ett suboptimalt antal gånger. En begränsning i hur mycket fuktigheten tillåts modifieras förändras under initialiseringsprocessen och fungerade inte som avsett. Dessutom, jämförese med radiosonddata pekar på att relativa fuktighetsgränserna för villket moln bildas inledningsvis inte ansattes korrekt. Effekterna av metoden kunde vara i över 12 timmar, men denna studie pekar på ytterligare troliga förbättringsmöjligheter i HARMONIE-AROME genom införande av reviderad version av metoden samt förbättrade satellitprodukter.

Orientador: Marcos César de Oliveira Santos / Banca: Marco Aurélio Pizo Ferreira / Banca: Olavo Nardy / Resumo: A choca-do-planalto (Thamnophilus pelzelni Hellmayr, 1924) é um Thamnophilidae insetívoro que ocorre da área central do Brasil até o Nordeste. É considerada uma espécie comum e não está ameaçada de extinção. Informações sobre aspectos da área de vida são escassas, e assim torna-se necessário investir em esforços de pesquisas. O objetivo deste estudo foi estimar o tamanho da área de vida da choca-do-planalto e comparar o tamanho da área de vida entre o período chuvoso não reprodutivo, período seco não reprodutivo e período chuvoso reprodutivo. O estudo foi realizado dentro de uma grade de 30 ha na Estação Ecológica de Jataí (21°30' - 21°40'S e 47°40' - 47°50'W), município de Luiz Antônio, SP, entre fevereiro de 2009 e janeiro de 2010. Para a demarcação das áreas de vida, os indivíduos de T. pelzelni foram capturados com redes de neblina e marcados com uma anilha padrão CEMAVE e duas anilhas coloridas. As trilhas da grade eram percorridas e os indivíduos detectados tinham sua sequência de anilhas identificada com a ajuda de um binóculo (10x50) e a localização era determinada com ajuda de um GPS. Para estimar a área de vida foi utilizado o Minimo Poligono Convexo (MPC) com probabilidade de 100% e o Kernel Fixo (KF) 95% e 50% referentes, respectivamente, a área de vida e área core. Para comparar o tamanho da área de vida nos três períodos amostrados foi feito análise de variância para medidas repetidas (RM-ANOVA) e o teste de Tukey foi usado para identificar qual média diferiu significativamente entre si. O tamanho da área de vida calculada pelo MPC variou de 2,7 a 4,8 ha, com média de 3,3 ± 0,6 ha Pelo estimador de KF 95% a área de vida variou de 3,4 a 7,0 ha, com média de 4,7 ±1,1 ha. A área core (KF 50%) apresentou média de 1,1 ± 0,3 ha. Os tamanhos das áreas de vida variaram significativamente entre os três períodos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Planalto Slaty-Antshrike (Thamnophilus pelzelni Hellmayr, 1924) is an insectivore Thamnophilidae that occurs in the central area of Brazil to the northeast of the country. It is a common species and considered not threatened. Information about aspects of home range is scarce. The aim of this study was to estimate the home range of Planalto Slaty-Antshrike and compare the extent of home range among the non-reproductive rainy season, non-reproductive dry season and breeding rainy season. Data collection occurred in a grid of 30 ha in Jataí Ecological Station (21 ° 30 '- 21 ° 40'S and 47 ° 40' - 47 ° 50'W), municipality of Luiz Antônio, SP, between February 2009 and January 2010. Individuals of T. pelzelni were captured with mist nets and banded with a numbered aluminum leg band (pattern CEMAVE) and with two colored bands. Each track of the grid was traversed and in each contact, individuals detected had their sequence of washers identified with the aid of binoculars (10x50) and the location determined with the use of a GPS. The Minimum Convex Polygon (MCP) was applied with a probability of 100% and Fixed Kernel (FK) 95% and 50% concernig, respectively, the home range and core area. To compare the extent of home range in three sampling periods, analysis of variance was performed for repeated measures (RM-ANOVA), and Tukey test to identify which average differ significantly. The size of home range calculated by the MCP ranged from 2.7 to 4.8 hectares, with an average of 3.3 ± 0.6 ha. To apply the FK estimator at 95% of probability, the home range ranged from 3.4 to 7.0 ha, with a rough average of 4.7 ± 1.1 ha. The core area (FK 50%) resulted 1.1 ± 0.3 ha. The extent of the home ranges altered significantly between three sampling periods (MCP ˂ P 0.001; FK 95% P ˂ 0,001, 50% FK ˂ P 0.001). Tukey test exhibited that the home ranges were significantly larger during the dry... (Complete abstract click electronic access below) / Mestre

A Lei Federal n. 9.985/2000 regulamentou o artigo 225, §1º, inciso III da Constituição Federal que prevê a criação de espaços territoriais especialmente protegidos, em todas as unidades da Federação. A legislação infraconstitucional, que criou o Sistema Nacional de Unidades de Conservação (SNUC) concentra em um único documento diferentes categorias de Unidades de Conservação (UCs), ordenando os conceitos e classificações que anteriormente se confundiam em leis esparsas. Mesmo com a previsão legal, que impulsionou a criação de UCs em todo o Brasil é importante avaliar se essas áreas protegidas, além de serem criadas, estão sendo geridas e implementadas efetivamente. Dessa forma, o presente estudo se propôs a avaliar a eficácia do SNUC no processo histórico da Estação Ecológica Juréia-Itatins, com relação à conservação da sociobiodiversidade. A escolha da área de estudo justifica-se pela complexidade do seu contexto histórico caracterizado por sucessivas alterações nas categorias de unidades de conservação e as consequências observadas na proteção à biodiversidade e às comunidades locais. A pesquisa em questão optou pela estrutura de estudo de caso e pela abordagem qualitativa para atingir os objetivos pretendidos. Os recursos metodológicos utilizados para a coleta de dados foram a pesquisa bibliográfica, a documental e a pesquisa de campo, esta última realizada mediante instrumento da entrevista semi-estruturada. A eficácia da referida lei foi avaliada a partir de indicadores que emergiram da própria legislação analisada. Os resultados indicam a ineficácia de quase todos os indicadores analisados na EEJI, confirmando dentre outros fatores, um quadro de ineficiência da política ambiental estadual na gestão das UCs. / The Federal Law n. 9.985/2000 regulated article 225, § 1º, III of the Federal Constitution which provides the establishment of territorial spaces specifically protected, in all units of the Federation. This legislation, which created the National System of Units Conservation (SNUC) focuses different categories on a single document of units conservation (UCs), ordering the concepts and classifications which previously merged in other laws. Even with the legal provision, that spurred the creation of UCs throughout Brazil, is important to assess whether these protected areas, besides being created, have been managed and implemented effectively. Thus, the present study was to evaluate the effectiveness of SNUC in the historical process of Jureia-Itatins Ecological Station, with respect to conservation sociobiodiversity. The choice of the study area is justified by the complexity of its historical context characterized by successive changes in the categories of units conservation and the consequences seen in protecting biodiversity and local communities. The research in question opted to structure the case study and the qualitative approach to achieve the intended goals. The methodological tools used for data collection were the references of the published literature, documentary and field research, with semi-structured interview. The effectiveness of this Law was assessed from indicators that emerged from the legislation itself analyzed. The results [has] suggested the ineffectiveness of almost all indicators analyzed in EEJI, confirming among other factors, the inefficiency of state environmental policy in the management of UCs.

Data are presented from an automatic weather station on the Brintnell-Bologna Icefield that operated from August 2014 to August 2016 in Nahanni National Park Reserve. This location is notable for being the northernmost mass balance alpine study location of the federal government’s glaciology program (NRCan/GSC). The link between atmospheric forcing at the synoptic scale and response at the glacier surface has been shown to be strongly dependent on continentality and latitude. In this region, however, many aspects of the physical processes controlling the interaction between atmospheric forcing and snowpack response are virtually unknown, especially at the daily to hourly timescale. The character of snowfalls during the accumulation seasons for this icefield are investigated using high resolution time series from two acoustic snow depth sensors and other relevant meteorological parameters. It is found that the most drastic changes in snow depth occur from infrequent large snowfalls. Using an adaption of an Environment Canada snow depth algorithm, snowfall events are identified and their timing is quantified based on a system of thresholds, running averages and ratios between the snow depth sensors. Synoptic conditions are examined using meteorological reanalysis data and trajectory analysis to determine the moisture origin and pathway. / Graduate

One of the biggest problems of today is transport, especially in the cities. The transport has many negative effects, like congestions, pollution and others. The solutions of this situation are very hard and they have no integrated methodology. This doctoral thesis has two theoretic objectives: 1. set up new concept of city logistics, which means the integration of several disciplines, important for integrated admission to soluted problems 2. validate the pertinence of simulation in the new koncept of city logistics, created in objective 1 The thesis has also one concrete objektive, which is the validation of effectiveness of one project. The investigated project is removal of the train station in Brno.

Made available in DSpace on 2016-03-15T19:48:26Z (GMT). No. of bitstreams: 1 Flavio Carlos Rodrigues de Barros.pdf: 491681 bytes, checksum: ef65386c8ce66807f899163e0387cb6d (MD5) Previous issue date: 2013-07-30 / The dissertation proposes identifying objectives that evangelical radio stations want to achieve with your program schedule. We argue that currently uses this means of mass communication, not only as a strategy for evangelization. But yes, as a political, commercial and educational. The thesis proposes a study on the definition of mass communication and its application within sight of schools of thought Frankfurt and Toronto. The theme of the history of radio offers a historical study on the radio between the years 1873 and 1920. We defend that the radio came up with the objective of meeting the need for communication at a distance without physical contact. It was first introduced in Brazil in order to elevate the culture and education of the Brazilian people. The theme of the objective of evangelical radio stations proposes to identify the profile of evangelical radio stations of Rio de Janeiro through a study of the three most listened radios evangelical city according to IBOPE. / Esta dissertação propõe identificar que objetivos as estações de rádio evangélicas pretendem atingir com sua grade de programação. Discutimos que atualmente utiliza-se este meio de comunicação de massa, não apenas como estratégia de evangelização. Mas sim, como espaço político, comercial e educacional. O presente trabalho propõe um estudo sobre a definição do termo comunicação de massa e sua aplicação dentro da visão das escolas de pensamento de Frankfurt e de Toronto. O tema da história do rádio propõe um estudo histórico sobre o rádio entre os anos 1873 e 1920. Defendemos que o rádio surgiu com o objetivo de atender a necessidade de comunicação à distância sem contato físico. E foi implantado no Brasil primeiramente com o intuito de elevar a cultura e a educação do povo brasileiro. O tema dos objetivos das estações de rádio evangélicas propõe identificar o perfil das estações de rádio evangélicas do Rio de Janeiro por meio de um estudo das três rádios evangélicas mais ouvidas da cidade segundo o IBOPE.

Este trabalho teve por objetivo relacionar a estrutura da comunidade fitoplanctônica com as variáveis físicas, físico-químicas e químicas das Lagoas de Maturação da Estação de Tratamento de Esgotos da Universidade de Caxias do Sul, no período de um ano. Foram considerados os atributos da comunidade (riqueza, composição, densidade, diversidade e eqüitabilidade), suas relações com as variáveis abióticas (temperatura do ar e da água, turbidez, transparência da água, pH, condutividade elétrica, OD, DBO5 total e solúvel, DQO total e solúvel, sólidos suspensos totais e voláteis, nitrato, nitrito, nitrogênio amoniacal e fósforo total), além da precipitação pluviométrica e da intensidade do vento. As amostragens foram mensais no período de agosto/05 a julho/06. As análises quali-quantitativas do fitoplâncton foram realizadas em microscópio binocular, sendo que, para a quantificação, utilizou-se a câmara de Sedwick-Rafter. Na análise quali-quantitativa foram identificados 242 táxons em níveis genérico, específico e infra-específico.A comunidade fitoplanctônica mostrou-se semelhante nos doze meses amostrados, sendo que as classes Chlorophyceae e Zignematophyceae foram as mais representativas nos períodos mais quentes. No período de temperaturas mais baixas, predominaram as classes Cianophyceae, Bacillariophyceae e Euglenophyceae. Os gêneros com maior densidade anual, dentre as classes estudadas, foram representados por: Chlamydomonas, Synechocystis, Surirella, Euglena e Cosmarium. As espécies com maior densidade anual, dentre os gêneros registrados, foram: Chlorella miniata, Synechocystis aquatilis, Surirella ovata, Lepocinclis fusiformis e Cosmarium sp c. Os resultados mostraram que ocorreu uma variação sazonal no "standing-stock" com um máximo no outono e verão e um mínimo na primavera e no inverno. O "standing-stock" foi de 589.060 ind./mL a 1.181.498 ind./mL, com o valor médio anual de 898.166 ind./mL. Os índices de diversidade e eqüitabilidade, bem como os valores de riqueza, apresentaram uma pequena diferença entre as estações do ano e entre as estações amostradas, porém revelaram uma maior diferença entre os meses amostrados.Na análise de agrupamento, tanto a riqueza quanto a abundância de indivíduos encontradas na Entrada da Lagoa de Maturação 1 (ELM1) e Saída da Lagoa de Maturação 1 (SLM1) foram similares entre si, no entanto diferiram da encontrada na Saída da Lagoa de Maturação 2 (SLM2). Essa diferença foi determinada, provavelmente, pelas variações existentes entre as variáveis ambientais estudadas da Lagoa de Maturação 1 (LM1) e da Lagoa de Maturação 2 (LM2) e pelo tempo de detenção hidráulica de cada Lagoa de Maturação. Na análise de regressão linear múltipla, constatou-se que a turbidez foi a única variável que influenciou diretamente na riqueza, abundância e diversidade fitoplanctônica. Isso ocorreu, provavelmente, porque essa variável reduz a penetração da luz, fator que controla a temperatura e a fotossíntese, alterando, com isso, a estrutura da comunidade fitoplanctônica. / The aim of this paper is to establish a relationship between the phytoplanktic’s community structure with the physical, physical-chemical and chemical variables of the Maturation Lakes from Station Sewerage Treatment of Caxias do Sul University, over a year. It has been considered the community’s features (richness, composition, density, diversity and equitability), their relationships between the abiotic variables (air and water temperature, turbidity, water transparency, pH, eletric conductivity, DO, total and soluble BOD5, total and soluble COD, total and volatile suspendend solids, nitrate, nitrite, ammonium nitrogen and total phosphorus), as well as the rainfalls and the wind’s intensity. The samples were taken monthly from August 2005 to July 2006. The quali-quantitative phytoplankton analysis were carried out in a binocular optic microscope and for the quantification a of Sedwick-Rafter’s chamber was used as well. In the quali-quantitative analysis were identified 242 taxa in generic levels, specific and infra-specific. The phytoplanktic community was similar all over the 12 months sampled, however the Chlorophyceae and Zignematophyceae were more significant in the hot months. In the low temperature months it could be perceived the Cianophyceae, Bacillariophyceae and the Euglenophyceae more significantly.The genre with higher annual density among the classes been studied were: Chlamydomonas, Synechocystis, Surirella, Euglena and Cosmarium. The species with highest annual density among the classes been studied were: Chorella miniata, Synechocystis aquatilis, Surirella ovata, Lepocinclis fusiformis and Cosmarium sp c. The results showed a seasonal variation in the standing-stock with a maximum in the fall and summer and a minimum in the spring and winter. The standing-stock was 589.060 ind./mL a 1.181.498 ind./mL, with the medium annual rate of 898.166 ind./mL. The diversity and equality levels, as well as the richness values showed a slight difference among the seasons of the year themselves and the seasons sampled, however, they showed a bigger difference in the sampled months. In the grouping analysis, either the richness or the abundance of individuals found in the entrance of Maturation Lake 1 (EML1) and the exit of the Maturation Lake1 (SML1), were alike each other, however, they differ from those found in the exit of the Maturation Lake 2 (SML2). This difference was probably defined by the remaining environmental variables studied from Maturation Lake 1 (ML1) and from the Maturation Lake 2 (ML2) and for the time of hydraulical retention of each Maturation Lake. In the linear multiple regression analysis, the results showed that the turbidity was the only variable that influenced directly in the phytoplanktic’s richness, abundance and diversity. That probably might have happened due to the turbity which reduces the light penetration, a factor which controls the temperature, the photosyntesis, changing that way the structure of the phytoplanktic community.

O nivelamento trigonométrico com estação total é uma técnica que tem sua aplicação revigorada em situações que até pouco tempo atrás, por razões de precisão, somente podiam ser atendidas com uso de nivelamento geométrico. A NBR 13.133 inclui este tipo de nivelamento em uma única classe e estabelece tolerâncias muito altas, e por essa razão limita a sua especificação por empresas contratantes. Neste trabalho, avaliou-se a precisão do nivelamento trigonométrico usando estações totais de baixa e média precisão, comparando as diferenças de níveis obtidos por nivelamento geométrico. Na avaliação foram consideradas as influências de alguns fatores na propagação dos erros: a obtenção da altura do instrumento, os efeitos atmosférico, o posicionamento e altura dos alvos, a precisão dos equipamentos e as distâncias de visadas. Os resultados possibilitaram definir as distâncias máximas de visada nas condições avaliadas, em que alcança a tolerância do nivelamento geométrico IIN / The trigonometrical leveling with total station is a technique that has been increased in situations in that even some time, for reasons of precision, the use of the leveling was demanded. The NBR 13.133 includes this trigonometrical leveling in a single class and it establishes very high tolerances, and for that reason it limits its specification for contracting companies. The precision of the trigonometrical leveling was evaluated using total stations of low and intermediate precision, comparing the differences of levels obtained by leveling. In the evaluation the influences of some factors were considered in the propagation of the errors: the instrument height determination, the atmospheric effects, the positioning and staff height determination, the precision of the equipments and the distances of staff. The results made possible to define the sight maximum distances in the evaluated conditions, in that it reaches the IIN tolerance leveling

A pesquisa consiste na analise geográfica com ênfase ao Patrimônio Geomorfológico da Estação Ecológica Serra Geral do Tocantins e entorno localizada entre a porção leste do Estado do Tocantins e a porção oeste do Estado da Bahia, região conhecida como Jalapão. Além da analise geográfica, a pesquisa tem como objetivo principal verificar a importância do seu “Patrimônio Geomorfológico” na gestão e preservação desta Unidade de Conservação da Natureza bem como subsidiar a elaboração de seu Plano de Manejo. Para atingir o objetivo proposto adotou-se como procedimento metodológico o uso do Geoprocessamento com a organização de um banco de dados via Sistema de Informação Geográfica (SIG) utilizando o software Sistema de Processamento de Informações Georreferenciadas (SPRING) e as imagens de satélites (Cbers e Landsat) e de radar Shuttle Radar Topography Mission (SRTM), além de cartas topográficas, mapas e arquivos digitais. Também foram realizados diversos trabalhos de campo apoiados pelo uso de receptores do Sistema de Posicionamento Global (GPS). O estudo apresenta informações e organização de mapas temáticos sobre aspectos do clima, relevo, hidrografia, geologia, solos, geomorfologia e uso e ocupação da terra, além de uma descrição detalhada das feições geomorfológicas da área de pesquisa, com ênfase nos seus aspectos morfogenéticos, morfoestruturais e morfométricos. Os resultados demonstram que a abordagem geográfica e o Patrimônio Geomorfológico da área de pesquisa são de suma importância para o melhor entendimento do valor ecológicoambiental dos aspectos abióticos, e devem ser considerados na gestão e conservação ambiental da Estação Ecológica Serra Geral do Tocantins, bem como no fornecimento de subsídios a elaboração do seu Plano de Manejo. / This research consists of the geographic analysis emphasizing the Geomorphologic Heritage of the Ecological Station Serra Geral do Tocantins and surroundings, located between the eastern portion of Tocantins State and western portion of Bahia State, region that is known as Jalapão. Besides the geografic analysis, the main objective of the research is to chek the importance of its "Geomorphologic Heritage" in the management and preservation of Nature Conservation Unit as well as the elaboration of its Management Plan. To achieve the proposed objective a methodological procedure was adopted by using GIS with the organization of a database via Geographic Information System (GIS) using the System Georeferenced Information Processing software (SPRING) and the images of satellites (CBERS and Landsat) and Shuttle Radar Topography Mission (SRTM), besides topographic letters, maps and digital files. Many field works have also been performed by the use of receptors Global Positioning System (GPS). The study presents information and organization of thematic maps on climate aspects, topography, hydrology, geology, soils, geomorphology and the use and occupation of land, plus a detailed description of the geomorphological features of the area of research, emphasizing their morphogenetic aspects, morphostructural and morphometric. The results demonstrate that the geographical approach and the Geomorphological Heritage area of the research is very importance for a better understanding of the ecological and environmental aspects abiotic value, and should be considered in the management and conservation of the Estação Ecológica Serra Geral do Tocantins in addition to provide information to prepare its Management Plan.

Microorganisms are known to tolerate a variety of extreme environments, such as high and low pH, desiccation and a wide range of temperatures that would prove uninhabitable for most eukaryotic cells. However, extreme radiation exposure is a ubiquitous hazard to pro- and eukaryotic viability. Ionising and non-ionising radiation, and their associated high energies, cause damage to a cell in the form of DNA double-strand breaks, membrane deterioration, and lethal mutations. Radiation also induces secondary effects such as the production of reactive oxygen species, which attack and degrade organic compounds. It is therefore not surprising that radiation is considered by the scientific community to be one of the main influencing factors when regarding habitability on the early Earth, as well as other planets, such as present-day Mars. This thesis explores the response of select microbes that have been exposed to extreme radiation environments, i.e. both high and ultra-low radiation. Understanding how radiation affects the geochemical environment is key to the assessment of its potential to support life and to harbour molecules associated with life. The effect of radiation-induced photochemistry on the early terrestrial and present-day Martian surface is explored in conjunction with Fenton chemistry. Iron oxides are abundant on both Earth and Mars and act as catalysts in Photo-Fenton reactions, enabling the production of free radicals. The resulting consequences for habitability are shown to be antagonistic, with iron oxide enabling both the protection or destruction of cells, depending on the local geochemistry. In addition, the photo-reactivity of perchlorate is investigated. The UV-induced activation of the strong oxidant, and recently confirmed Martian surface constituent, is demonstrated, revealing its severe bacteriocidal effect on microbes. It is also shown to significantly reduce microbial viability when combined with further Martian soil constituents and components required for Photo-Fenton chemistry. In order to accurately analyse the effects of low earth orbit radiation on prokaryotic life, cyanobacterial samples were attached to the outside of the International Space Station as part of the EXPOSE-R2 mission for 1.5 years. The samples were subjected to various conditions, including exposure to a minimally filtered space radiation environment and simulated Mars conditions. The experiment is designed to test the protection that biogenic and non-biogenic substances may provide to cells. The results in this work present the post-flight analysis of the samples and demonstrate the ability of these substances to maintain cyanobacteria viability. They also show that the cyanobacterial cells themselves can effectively act as a shield for a secondary, co-cultured bacteria species. On the other end of the radiation dose scale, this work addresses the gaps in knowledge with regard to the little-understood effects of low, sub-background radiation on prokaryotes. Using the Boulby Underground Lab in the functioning Boulby Mine, Cleveland UK, microbes are cultivated under regulated, extremely low radiation environments to test multiple dose-response models. The results show no change in cell's growth rates or gradients in low radiation exposure when compared to surface-dose controls. They also fail to exhibit any enhanced susceptibility to stress factors, such as UV irradiation, as suggested by previous work in the field. These experiments mark the first extensive and tightly controlled research into microbial responses in the near-absence of radiation. This work illustrates the importance of understanding both primary and secondary effects of radiation on microbes and begins to bridge the knowledge gap from both ends of the dose axis. These approaches show the far-reaching influence radiation has on astrobiologically relevant topics, such as habitat geochemistry and life detection, and demonstrate the capacity of life to survive in extreme radiation environments.