In the master’s thesis IEEE 802.15.4 Range measurements I want to find out, whether atmospheric conditions have influence over the quality of communication between two ZigBee modules. I would like found the answer by long-time test, because I can’t found the proper place for the measuring, I must found the answer in the literature. In the second part of the master’s thesis I measuring, whether placing one of the module in the car have influence over the quality of communication. The module was placing in the various places in the car, on a dashboard, on a guest-passenger’s seat, in a pocket before guest-passenger and in luggage compartment. The car for the measuring was used Renaul Scénic my. 2004.

Viena svarbiausių daugelio didesnių miestų ekologinių problemų - vis didėjanti oro tarša azoto dioksidu. Pagal taršą azoto oksidais, galima spręsti apie bendrą miesto oro užterštumą, todėl labai svarbu kontroliuoti šio teršalo koncentraciją ore. 2005 - 2007 metais Mažeikių mieste buvo atliktas tyrimas, kurio pagrindinis tikslas - ištirti azoto dioksido koncentraciją Mažeikių mieste skirtingais sezonais bei aptarti meteorologinių sąlygų įtaką azoto dioksido koncentracijos sklaidai. Azoto dioksido koncentracijai nustatyti buvo naudotas pasyvaus kaupimo metodas. Atlikus tyrimus paaiškėjo, kad didžiausia koncentracija buvo nustatyta 2005 metų vasaros sezono metu (14,2 μg/m3). Tam įtakos turėjo mažas kritulių kiekis, aukšta temperatūra, bei vyravusi vėjo kryptis, nešusi teršalus nuo AB „Mažeikių naftos“. Panašūs rezultatai gauti ir 2006 metų žiemos sezono metu (14,0 μg/m3). Žiemos metu dažnai stebimos didesnės teršalų koncentracijos, kurios išsiskiria iš nuosavų namų šildymo sistemų. Mažiausia koncentracija buvo nustatyta 2007 metų rudens sezono metu (7,2 μg/m3) . Panaši koncentracija nustatyta ir 2007 metų vasarą (7,9 μg/m3). Tai lėmė palankios teršalų sklaidai meteorologinės sąlygos: didesnis kritulių kiekis, didesnė santykinė drėgmė. Nagrinėjant meteorologinių sąlygų įtaką azoto dioksido koncentracijos pasiskirstymui, statistiškai reikšmingi ryšiai gauti tarp vidutinio vėjo greičio ir azoto dioksido koncentracijos rudens sezono metu (r = -0,8729; p = 0,0533), kritulių... [toliau žr. visą tekstą] / The most important problem of biggest towns is air pollution of nitric dioxide. By pollution of nitric dioxide we can decide about general towns polltution. In the Mažeikiai town was explore distribution of nitric dioxide concentration. Nitric dioxide concentrations were gauge in the different seasons. We used a passive sampling method and triethanolamine as an absorbent. After analysis we get such rezults: the maximum concentration was fixed in the summer (14,2 μg/m3). It could impact low rainfall, high temperature and dominant wind which pollution drived from AB „Mažeikių nafta“. A similar results were assessed in the winter (2006 year) (14,0 μg/m3). Minimum value was fixed in the autumn (2007 year) (7,2 μg/m3). Similar concentration was fixed in the summer too (7,9 μg/m3). It impacted atmospheric conditions: high humidity. Reliable results were get between wind rate and nitric dioxide concentrations in the autumn season (r = -0,8729; p = 0,0533), precipitation and nitric dioxide concentrations in the spring (r = -0,9983; p = 0,0374) also precipitation and nitric dioxide concentrations in all seasons r = -0,7897; p = 0,0066). But in the neither season was not exceed the quotas of concentration (40 μg/m3).

The objective of this study was analyze the concentrations of nitrogen oxides in the center of the metropolitan area in Maceió, Alagoas. The data were collected from chemical parameters using a NOx analyzer (NO + NO2) API Model 200 A using the chemiluminescence method, and to monitore the atmospheric conditions (physical parameters) was used a WeatherLink Pro2 weather station from Davis Instruments (USA), where its sensors were 2 meters in height above the ground. Monitoring for the parameters had an average interval of 10 minutes. Nitrogen oxides concentrations are shown sensitive to weather changes. The highest frequencies of NO concentrations were 43,8% ranging from 10-15 ppbv and NO2 concentrations were 46,6% between 0 and 2 ppbv. It was evident that the highest concentrations were obtained during the week. The NO2 and NO concentrations for 15/07 (Thursday) during the day were nearly 309% and 153.5% higher than 12/07 (Sunday), respectively. The motor vehicles were the main source of emissions due to high atmospheric pressure increased concentrations, and with low pressures the concentrations were decreased. During the night, the weather provided some chemical reactions that were sink of NOx, so having in this period low daily concentrations. During the day, the intensity of solar radiation and the presence of cloud cover contributed to significant attenuation of concentrations of these oxides, allowing the photolysis of NO2 to form secondary pollutants harmful to health. / Fundação de Amparo a Pesquisa do Estado de Alagoas / Com o objetivo de analisar as concentrações dos óxidos de nitrogênio no centro da Região Metropolitana de Maceió-Al, coletou-se dados dos parâmetros químicos utilizando um analisador de NOx(NO+ NO2) API Modelo 200 A através do método de quimiluminescência, e para o acompanhamento das condições atmosféricas (parâmetros físicos) utilizou-se uma estação meteorológica da WeatherLink Pro2 da Davis Instruments (E.U.A), no qual seus sensores ficaram a 2 metros de altura em relação ao solo. O monitoramento para ambos os parâmetros tiveram intervalo médio de 10 minutos. As concentrações dos óxidos nitrogenados se mostram sensíveis as mudanças meteorológicas. As maiores freqüências de concentrações de NO situaram no intervalo de 43,8 % com variações de 10-15ppbv e para NO2 tiveram 46, 6% entre 0 e 2 ppbv. Evidenciou que as maiores concentrações foram obtidas nos dias de semana, no dia 15/07 no período diurno, cerca de 309% para o NO2 e 153,5% de NO, superiores ao dia 12/07 (domingo) sendo os veículos automotores a principal fonte de emissão isto associado à alta pressão atmosférica aumentaram as concentrações, e inversamente quando ocorreram baixas pressões diminuíram as concentrações. Durante a madrugada, as condições atmosféricas propiciou algumas reações químicas que foram sumidouro dos NOx, assim, tendo nesse período relativamente as menores concentrações diárias. Durante o período diurno, a intensidade da radiação solar assim como a presença da nebulosidade contribuiu para atenuação significativa das concentrações desses óxidos, propiciando a fotólise do NO2 para formação de poluentes secundários, prejudiciais à saúde da população.

Two threats to bats are especially pervasive in the central Appalachian Mountains of the eastern United States: a fungal disease called White-nose Syndrome (WNS) and wind energy development. White-nose Syndrome has caused the death of millions of bats in North America, and multiple hibernating bat species are affected in the central Appalachians. Wind energy is one of the most rapidly-growing energy sources in eastern United States, and bats are often killed when they fly near wind turbines. Fatality rates at wind turbines is highest in bat species that migrate instead of hibernate. There is limited data on bats during the autumn and spring seasons in the central Appalachian Mountains, and the impacts of WNS and wind energy development may be exacerbated during these seasons. Therefore, I sought to determine patterns and drivers of activity for hibernating bat species during autumn and spring around hibernacula. Similarly, I set out to determine patterns and drivers of activity for migratory bat species during autumn and spring along mountain ridgelines in the central Appalachians. Lastly, I searched for evidence of potential WNS-induced changes in the summer ecology of the once common northern long eared bat. This study can help elucidate patterns of bat activity during largely understudied seasons. Furthermore, it can provide useful information needed by land managers to implement actions that could help alleviate and/or avoid potential additive negative impacts on bat species with existing conservation concerns. / MS

Acoustic communication in anurans plays a critical role in species recognition, defending territories and resources, and finding a mate. Anurans use a number of different call note types to communicate, from which the most notable are advertisement- and aggression calls. Optimum weather conditions are a precursor to the commencement of the breeding season for all frog species and their calling behaviour is therefore readily influenced by atmospheric conditions. Male frogs within a chorus also tend to call from territories within a specific range of distances from one another. The objectives of this study were to 1) determine a possible context in which call note types are produced, 2) to determine the effect of atmospheric conditions on calling behaviour and 3) to determine the spacing distances between males and females in a chorus of Queckett’s River Frog (Amietia quecketti). Pre-recorded note types were used in a playback experiment to determine a context for elicited responses. A context was derived for six of the responses. Advertisement (clicks and whines), aggression (creaks), encounter (tonal notes), territorial (whine-tonal notes), and release calls (squeaks) were described. Calls and atmospheric conditions were recorded and correlated for an entire breeding season. Water temperature, wind speed, humidity and barometric pressure had a significant effect on calling intensity. As water temperature decreased calling intensity increased, while increased wind temperature led to increased calling intensity. Amietia quecketti calls from the water, explaining the effect while increased wind speed decreases water temperature and can carry sound further. Both humidity and barometric pressure showed increased calling intensity only at specific levels. Humidity and barometric pressure have a direct effect on one another, which most likely causes the correlation between calling intensity and both these variables. In this study A. quecketti was shown to have breeding ponds for males and resting ponds and positions for non-gravid females. This prevents unwanted or unnecessary amplexus. Males showed much smaller and less variable territory sizes than females. This is most likely because males have a small range of optimal spacing distance while females move towards and away from males. The presence of vegetation resulted in smaller territories. This is possibly because smaller males act as satellite males and cannot be seen by larger males in vegetation. The size of males did not affect territory size. Males have a specific inter-male spacing distance regardless of size. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Acoustic communication in anurans plays a critical role in species recognition, defending territories and resources, and finding a mate. Anurans use a number of different call note types to communicate, from which the most notable are advertisement- and aggression calls. Optimum weather conditions are a precursor to the commencement of the breeding season for all frog species and their calling behaviour is therefore readily influenced by atmospheric conditions. Male frogs within a chorus also tend to call from territories within a specific range of distances from one another. The objectives of this study were to 1) determine a possible context in which call note types are produced, 2) to determine the effect of atmospheric conditions on calling behaviour and 3) to determine the spacing distances between males and females in a chorus of Queckett’s River Frog (Amietia quecketti). Pre-recorded note types were used in a playback experiment to determine a context for elicited responses. A context was derived for six of the responses. Advertisement (clicks and whines), aggression (creaks), encounter (tonal notes), territorial (whine-tonal notes), and release calls (squeaks) were described. Calls and atmospheric conditions were recorded and correlated for an entire breeding season. Water temperature, wind speed, humidity and barometric pressure had a significant effect on calling intensity. As water temperature decreased calling intensity increased, while increased wind temperature led to increased calling intensity. Amietia quecketti calls from the water, explaining the effect while increased wind speed decreases water temperature and can carry sound further. Both humidity and barometric pressure showed increased calling intensity only at specific levels. Humidity and barometric pressure have a direct effect on one another, which most likely causes the correlation between calling intensity and both these variables. In this study A. quecketti was shown to have breeding ponds for males and resting ponds and positions for non-gravid females. This prevents unwanted or unnecessary amplexus. Males showed much smaller and less variable territory sizes than females. This is most likely because males have a small range of optimal spacing distance while females move towards and away from males. The presence of vegetation resulted in smaller territories. This is possibly because smaller males act as satellite males and cannot be seen by larger males in vegetation. The size of males did not affect territory size. Males have a specific inter-male spacing distance regardless of size. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Introdução: As análises de controle ambiental de ar atmosférico são realizadas caracterizando principalmente a parte química dos aerossóis. Boa parte dos aerossóis são partículas vivas ou fragmentos de micro-organismos que utilizam o ar como veículo de dispersão. A natureza dessas biopartículas é diversa, podendo conter vírus, protozoários, bactérias, fungos e outros. Os fungos dispersos no ar são chamados de anemófilos. Como as informações sobre os anemófilos da cidade de São Paulo ainda são escassas, se faz necessário fazer um levantamento destes micro-organismos e suas relações com as condições atmosféricas e os poluentes presentes no ar, permitindo adicionar informações que poderão ser úteis para os modelos climáticos e de saúde, além de poder auxiliar novos estudos na área da epidemiologia ambiental, talvez como biomarcadores de poluição. Objetivo: Analisar a frequência de diferentes gêneros fúngicos na atmosfera da região metropolitana de São Paulo e correlacionar com as condições atmosféricas e os poluentes circulantes. Materiais e Métodos: A concentração de fungos e bactérias foi analisada no ar atmosférico de São Paulo em quatro pontos, três na cidade de São Paulo, sendo um no Instituto de Astronomia, Geofísica e Ciências Atmosféricas situado na Cidade Universitária, dois no bairro Cerqueira César distintos pela altitude (andar térreo e 23º andar) e na cidade de Ibiúna, no Bairro Votorantim. Os dados sobre os poluentes foram obtidos na Companhia Ambiental do Estado de São Paulo (Cetesb) e das condições atmosféricas foram obtidos no banco de dados do Ministério da Agricultura, Pecuária e Abastecimento do país (INMET). Durante as coletas utilizamos impactadores de ar. Foram coletadas 736 amostras, durante seis anos. Após as coletas, foi feita a análise da concentração de fungos e bactérias. Após crescimento, uma colônia de cada gênero por dia de coleta/ponto foi enviada para identificação, totalizando 1630 isolados. Durante o processo de identificação de gênero foram utilizadas características fenotípicas e as espécies do gênero Aspergillus foram identificadas pelo sistema Maldi-tof. Resultados: De acordo com os resultados obtidos, as condições meteorológicas da cidade de São Paulo influenciam diretamente na concentração de fungos dispersos no ar. A diversidade fúngica variou com a região estudada. Discussão: É difícil avaliar a importância individual de cada componente do ar devido à natureza dinâmica da atmosfera. O que se sabe é que as investigações sobre bioaerossóis fúngicos e a atenção que tem sido dada às suas relações com as condições atmosféricas e a poluição são escassas. Com os resultados obtidos foi verificado que a concentração de fungos se modifica de acordo com as condições ambientais levando a crer que eles podem ser utilizados como bioindicadores de poluição. Conclusão: Como os fungos presentes no ar atmosférico são sensíveis às condições atmosféricas e à exposição a poluentes, eles podem ser utilizados como marcadores de poluição, seu monitoramento associado ao controle de poluentes e condições atmosféricas fortalece as pesquisas relacionadas ao ar atmosférico. / Introduction: Atmospheric air environmental control analyzes are carried out mainly characterizing the chemical part of the aerosols. Much of the aerosols are live particles or fragments of microorganisms that use air as the dispersing vehicle. The nature of these bioparticles is diverse and may contain viruses, protozoa, bacteria, fungi and others. Fungi dispersed in the air are called anemophils. As the information about anemophils in the city of São Paulo is still scarce, it is necessary to survey these microorganisms and their relationships with atmospheric conditions and pollutants present in the air, allowing the addition of information that may be useful for climate models and health, in addition to being able to support new studies in the area of environmental epidemiology, perhaps as biomarkers of pollution. Objective: To analyze the frequency of different fungal genera in the atmosphere of the metropolitan region of São Paulo and to correlate with atmospheric conditions and circulating pollutants. Materials and Methods: The concentration of fungi and bacteria was analyzed in the air of São Paulo in four points, three in the city of São Paulo, one in the Institute of Astronomy, Geophysics and Atmospheric Sciences located in the University City, two in the district of Cerqueira César distinguished by altitude (ground floor and 23rd floor) and in the city of Ibiúna, Votorantim District. Data on the pollutants were obtained from Companhia Ambiental do Estado de São Paulo (Cetesb) and the weather conditions were obtained from the Ministry of Agriculture, Livestock and Supply (INMET) database. During the collection, we use air impactors. A total of 736 samples were collected for six years. After collection, the concentration of fungi and bacteria was analyzed. After growth, a colony of each genus per day of collection/point was sent for identification, totaling 1630 isolates. During the process of genus identification, phenotypic characteristics were used and the species of the genus Aspergillus were identified by the Maldi-tof system. Results: According to the results obtained, the meteorological conditions of the city of São Paulo directly influence the concentration of fungi dispersed in the air. Fungal diversity varied with the studied region. Discussion: It is difficult to assess the individual importance of each component of air due to the dynamic nature of the atmosphere. What is known is that research on fungal bioaerosols and the attention paid to its relations with weather and pollution are scarce. With the results obtained, it was verified that the fungi concentration modifies according to the environmental conditions leading to the belief that they can be used as bioindicators of pollution. Conclusion: As fungi present in atmospheric air are sensitive to atmospheric conditions and exposure to pollutants, they can be used as pollution markers; their monitoring associated with pollutant control and atmospheric conditions strengthens atmospheric air-related research.

This master’s thesis deals with creating a real-time simulation model of an aircraft piston engine with emphasis on heating and cooling of the engine cylinders. First part of this thesis focuses on characteristics of aircraft engines and differences with regular automotive engines. The next chapter describes the dependence of engine parameters on atmospheric conditions. The description of the real time model itself follows next. The results of the simulation model are presented and analysed at the end of this thesis.

Klima und Wetter üben einen tief greifenden Einfluss auf die menschliche Gesundheit aus. Die prognostizierten Folgen des Klimawandels haben Forschung auf diesem Gebiet in den Mittelpunkt des wissenschaftlichen Interesses gerückt. Bis zum jetzigen Zeitpunkt konnten verschiedene Studien einen Zusammenhang zwischen atmosphärischen Zuständen und Mortalität aufzeigen. Jedoch bezieht sich der Großteil dieser Forschung auf die Industrieländer der Mittelbreiten und Erkenntnisse aus solchen Arbeiten erlauben nur wenige Schlussfolgerungen über die Beziehung zwischen Atmosphäre und Gesundheit in tropischen Entwicklungsländern. Das vorrangige Ziel dieser Arbeit war es, das Verständnis über atmosphärische Einflüsse auf Sterblichkeit in Bangladesch, einem tropischen Land mit niedrigen sozioökonomischen Standards und starken Urbanisierungsprozessen, zu erweitern. Zentralen Bestandteil der Arbeit bilden umfangreiche Analysen zu atmosphärischen Einflüssen auf Mortalität mittels verschiedener Generalisierter Linearer und Additiver Modelle. Im Allgemeinen zeigt die Studie einen starken Zusammenhang zwischen atmosphärischen Zuständen und Mortalität auf. Mittel- bis langfristige saisonale Effekte ebenso wie unmittelbarere kurz- bis mittelfristige thermische Effekte wurden verdeutlicht. Trotz des tropischen Klimas wurde eine ausgeprägte Übersterblichkeit im Winter und bei niedrigen Temperaturen beobachtet. Dennoch wurde in einigen Fällen ein sekundäres Sommermaximum und ein Anstieg der Mortalität bei erhöhten Temperaturen gefunden. Insbesondere Gesamt- und kardiovaskuläre Mortaliät in Städten zeigte einen starken und lang andauernden Anstieg in Folge von Hitze. Ebenso waren Bevölkerungsgruppen über 65 Jahren stark von hitzebedingter Mortalität betroffen. Intensiven Urbanisierungstendenzen, die Alterung der Gesellschaft, die Zunahme kardiovaskulärer Erkrankungen sowie der Anstieg der Temperatur in Folge des Klimawandels legen nahe, dass schädlichen Hitzeeffekte in Zukunft zunehmen werden. / Climate and weather have profound effects on human health. With the projected consequences of climate change, research on the health-atmosphere relationship has increasingly been brought into the focus of scientific attention. To date, several studies have established a relationship between atmospheric short- or long -term conditions and human mortality. Nevertheless, the majority of scientific evidence refers to industrialised countries located in the mid-latitudes. The insights gained from these studies permit few conclusions to be drawn about the atmosphere-health relationship in tropical developing countries. The primary objective of this thesis was to advance our understanding of atmospheric effects on mortality in Bangladesh, a tropical country with low socio-economic status and strong urbanisation processes. An extensive analysis of atmospheric short- and long-term effects on mortality was conducted using various generalised linear and additive models. Generally, this thesis revealed a strong association between atmospheric conditions and mortality. Mid- to long-term seasonal effects were demonstrated as well as more immediate short- to mid-term thermal effects. Despite the tropical climate associated with constantly high temperatures, a strong dominance of winter and cold-related excess mortality was observed. Nevertheless, a secondary summer maximum and an increase in mortality with elevated temperatures were observed for several strata. In particular, all-cause and cardiovascular mortality in urban areas was found to be subject to intense and long-lasting heat effects. Likewise, the elderly population above 65 years was subject to heat-related mortality. Given the strong urbanisation trends, the ageing of populations, the increase in cardiovascular diseases, and the projected consequences of climate change adverse heat effects are likely to become more prevalent in Bangladesh and other developing countries.

Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-05-12T16:01:36Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_gabriela_lameu_moreira.pdf: 48934124 bytes, checksum: 7e62f6ed70d4fb9e308cbc0b8671374f (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-05-12T21:23:26Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_gabriela_lameu_moreira.pdf: 48934124 bytes, checksum: 7e62f6ed70d4fb9e308cbc0b8671374f (MD5) / Made available in DSpace on 2017-05-12T21:23:26Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_gabriela_lameu_moreira.pdf: 48934124 bytes, checksum: 7e62f6ed70d4fb9e308cbc0b8671374f (MD5) Previous issue date: 2015-02-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Este trabalho teve como objetivo principal analisar uma Linha de Instabilidade (LI) e um Complexo Convectivo de Mesoescala (CCM) e as condições atmosféricas que conduziram à sua formação, desenvolvimento e geração de descargas elétricas atmosféricas. Estes sistemas ocorreram entre os dias 17 e 19 de outubro de 2007, na região Sudeste do Brasil. A análise dos casos de estudo foi feita em quatro períodos: pré-formação, ocorrência da LI, período de transição e ocorrência do CCM. Para a obtenção dos resultados, a base de dados foi composta por dados de descargas atmosféricas e dados simulados, obtidos com o modelo WRF. As simulações com o modelo WRF foram feitas com três grades aninhadas, de resoluções horizontais de 36, 12 e 4km, que permitiram extrair os campos meteorológicos à grande escala, mesoescala e microescala, respectivamente, bem como o cálculo e análises de alguns parâmetros meteorológicos. Os dados de descargas atmosféricas foram obtidos pela RINDAT (Rede Integrada Nacional de Detecção de Descargas Atmosféricas), que foram sobrepostas às imagens de satélite e aos campos meteorológicos. Dentre os resultados obtidos, observou-se que a região onde os sistemas se formaram e desenvolveram estava propícia para a ocorrência de tempestades, apresentando grande umidade, confluência de ventos, índices de instabilidades com valores que atestavam o potencial de desenvolvimento de tempestades. As condições de grande escala associadas à ocorrência da LI e do CCM apresentaram diferenças e semelhanças, mas em ambos os casos, a atividade elétrica máxima esteve associada ao período mais favorável ao desenvolvimento de correntes ascendentes intensas. / This study had as main objective to analyze a Squall Lines (SL) and a Mesoscale Convective Complex (MCC) and the weather conditions that conducted to its formation, development and generation of lightning. These systems occurred between 17 and 19 October 2007, in Southeastern Brazil. The analysis of the case studies was done in four periods: pre-initiation, occurrence of SL, transition period and occurrence of MCC. To obtain the results, the database consisted of data lightning and simulated data, obtained using the WRF model. The simulations with the WRF model were made with three nested grids with horizontal resolutions of 36, 12 and 4 km, which allowed extracting the meteorological fields to large-scale, mesoscale and microscale, respectively, and an evaluation and analysis of some meteorological parameters. The lightning data were obtained by RINDAT (Rede Integrada Nacional de Detecção de Descargas Atmosféricas), which were superimposed on satellite images and meteorological fields. Among the results, it was observed that the region where the systems were formed and developed was favorable to the occurrence of storms, with high humidity, confluence of winds, instability indices with values that attested to the potential development of storms. The large-scale conditions for the occurrence of SL and MCC showed differences and similarities, but in both cases the maximum electrical activity was associated with more favorable period for the development of intense updrafts.