Observations show that the interannual variability of the Northern Hemisphere (NH) extratropical winter stratosphere is strongly correlated with the quasi-biennial oscillation (QBO) of tropical stratospheric winds, particularly during early winter. Most current general circulation models (GCMs) do not exhibit a QBO and therefore do not represent this important mode of tropical-extratropical interaction. In this study we examine the QBO-extratropical correlation using a 150-year GCM simulation in which a QBO occurs. Since no external forcings or interannual variations in sea surface temperatures are imposed, the modelled tropical-extratropical interactions represent an internal mode of atmospheric variability. The QBO itself is spontaneously forced by a combination of resolved and parameterized waves. The effects of this QBO on the climatological mean state and its interannual variability are considered, both by comparison with a control simulation (also 150 years in length, but with no QBO) and by compositing winters according to the phase of the QBO. Careful attention is given to the definition of QBO phase. Comparisons of the model results with observations (reanalysis data) are also made. QBO-induced changes in the climatological state of the model are found to have high statistical significance above the tropopause. In the extratropical winter stratosphere, these mean-state changes arise predominantly from the influence of the QBO on the propagation and dissipation of planetary-scale waves. This behaviour is shown to depend on the seasonal cycle, which argues for the usefulness of considering tropical-extratropical interactions in a GCM context. QBO influence on the interannual variability of the extratropical winter stratosphere is also seasonal, and the tropical-extratropical interaction is sensitive to the phase alignment of the QBO with respect to the annual cycle. This phase alignment is strongly affected by the seasonality of QBO phase transitions, which - due to the QBO being spontaneously generated, rather than having an imposed period - is somewhat realistic in the model. This leads to fluctuations in the strength of the modelled tropical-extratropical interaction occurring on a decadal timescale as an internal mode of atmospheric variability.

Observations show that the interannual variability of the Northern Hemisphere (NH) extratropical winter stratosphere is strongly correlated with the quasi-biennial oscillation (QBO) of tropical stratospheric winds, particularly during early winter. Most current general circulation models (GCMs) do not exhibit a QBO and therefore do not represent this important mode of tropical-extratropical interaction. In this study we examine the QBO-extratropical correlation using a 150-year GCM simulation in which a QBO occurs. Since no external forcings or interannual variations in sea surface temperatures are imposed, the modelled tropical-extratropical interactions represent an internal mode of atmospheric variability. The QBO itself is spontaneously forced by a combination of resolved and parameterized waves. The effects of this QBO on the climatological mean state and its interannual variability are considered, both by comparison with a control simulation (also 150 years in length, but with no QBO) and by compositing winters according to the phase of the QBO. Careful attention is given to the definition of QBO phase. Comparisons of the model results with observations (reanalysis data) are also made. QBO-induced changes in the climatological state of the model are found to have high statistical significance above the tropopause. In the extratropical winter stratosphere, these mean-state changes arise predominantly from the influence of the QBO on the propagation and dissipation of planetary-scale waves. This behaviour is shown to depend on the seasonal cycle, which argues for the usefulness of considering tropical-extratropical interactions in a GCM context. QBO influence on the interannual variability of the extratropical winter stratosphere is also seasonal, and the tropical-extratropical interaction is sensitive to the phase alignment of the QBO with respect to the annual cycle. This phase alignment is strongly affected by the seasonality of QBO phase transitions, which - due to the QBO being spontaneously generated, rather than having an imposed period - is somewhat realistic in the model. This leads to fluctuations in the strength of the modelled tropical-extratropical interaction occurring on a decadal timescale as an internal mode of atmospheric variability.

Kochia and biennial wormwood are two weeds sometimes found growing in sunflower fields that may be difficult to control. Weed management in sunflowers is usually conducted using a combination of herbicides and mechanical weed control methods. Some farmers are growing sunflowers in reduced tillage systems, which may rely solely on herbicides to manage weeds; however, the spectrum of broadleaf weeds that can be controlled with herbicides is limited. Field experiments were conducted across southern Manitoba to determine the effect of kochia and biennial wormwood density and relative time of weed seedling recruitment on sunflower growth and development, yield and seed quality and to determine action thresholds for each weed. Early emerging kochia (plants that emerged at about the same time as the sunflowers) reduced sunflower yield by as much as 82%, which was greater than early emerging biennial wormwood plants, which reduced yield by as much as 27%. At low weed densities, each kochia plant reduced sunflower yield by 0.52% and each biennial wormwood plant reduced sunflower yield by 0.17%. As the density of early emerging kochia plants increased, sunflower height, stem diameter, leaf counts and head diameter were reduced in some of the experiments. Increasing densities of early emerging biennial wormwood plants had minimal effect on sunflower growth and development. Early emerging kochia and biennial wormwood plants both had the potential to reduce sunflower seed size and seed weight, while late emerging kochia and biennial wormwood (plants that emerged after the 4-leaf stage of the sunflowers) did not affect sunflower seed quality. The action threshold (5% sunflower yield loss) for early emerging kochia was 10 plants per metre square and the action threshold for early emerging biennial wormwood was 36 plants per square metre in the combined site-year analysis. Kochia or biennial wormwood plants that recruited after the 4-leaf stage of the sunflower crop did not affect sunflower yield, or seed quality.

Kochia and biennial wormwood are two weeds sometimes found growing in sunflower fields that may be difficult to control. Weed management in sunflowers is usually conducted using a combination of herbicides and mechanical weed control methods. Some farmers are growing sunflowers in reduced tillage systems, which may rely solely on herbicides to manage weeds; however, the spectrum of broadleaf weeds that can be controlled with herbicides is limited. Field experiments were conducted across southern Manitoba to determine the effect of kochia and biennial wormwood density and relative time of weed seedling recruitment on sunflower growth and development, yield and seed quality and to determine action thresholds for each weed. Early emerging kochia (plants that emerged at about the same time as the sunflowers) reduced sunflower yield by as much as 82%, which was greater than early emerging biennial wormwood plants, which reduced yield by as much as 27%. At low weed densities, each kochia plant reduced sunflower yield by 0.52% and each biennial wormwood plant reduced sunflower yield by 0.17%. As the density of early emerging kochia plants increased, sunflower height, stem diameter, leaf counts and head diameter were reduced in some of the experiments. Increasing densities of early emerging biennial wormwood plants had minimal effect on sunflower growth and development. Early emerging kochia and biennial wormwood plants both had the potential to reduce sunflower seed size and seed weight, while late emerging kochia and biennial wormwood (plants that emerged after the 4-leaf stage of the sunflowers) did not affect sunflower seed quality. The action threshold (5% sunflower yield loss) for early emerging kochia was 10 plants per metre square and the action threshold for early emerging biennial wormwood was 36 plants per square metre in the combined site-year analysis. Kochia or biennial wormwood plants that recruited after the 4-leaf stage of the sunflower crop did not affect sunflower yield, or seed quality.

As Bienais de Arquitetura constituem meios institucionalizados para a difusão e promoção das diferentes realizações da arquitetura em lugares onde essas práticas acontecem, consolidando, ao longo dos anos, uma arraigada tradição em vários países da América Latina, ao ponto de se tornarem importantes eventos de arquitetura no contexto nacional, continental e global. Sobre o formato do concurso, as Bienais convocam revisões periódicas de uma parte da produção arquitetônica amparadas pelo reconhecimento do mais significativo dela. Entre as diferentes formas de premiação, os Grandes Prêmios Bienais comparecem quase de maneira consensual nesses eventos, sendo os máximos representantes da qualidade arquitetônica. Nesse contexto, este trabalho apresenta um panorama preliminar sobre as onze Bienais de Arquitetura mais emblemáticas do cenário Latino-americano, a fim de consolidar uma caracterização dessas práticas de difusão arquitetônica como conjunto. Por sua vez, o recorte temporal das últimas cinco Bienais ocorridas entre 2005 e 2015, partindo do mapeamento das obras ganhadoras dos grandes prêmios dessas Bienais, permitirá trazer alguns questionamentos que envolvem a natureza desses máximos prêmios no âmbito dessas mostras de arquitetura. Dentro das diversas variáveis que envolvem os laureados, nos aproximaremos de dois casos particulares de obras premiadas, com o intuito de identificar e tentar entender quais seriam as relações existentes entre o discurso da obra e o laudo do Júri, no contexto particular de cada Bienal. O nosso esforço, ao longo deste trabalho, estará norteado pela ideia de panorama contemporâneo dessas Bienais de arquitetura, como formas de avaliação e difusão de uma parte da produção arquitetônica atreladas à pratica disciplinar. / Architecture Biennials organize institutionalized means for diffusion and promotion of varied architecture achievements in places where those practices happen, consolidating along the years an ingrained tradition in several Latin American countries to an extent of becoming important events of architecture in the national, continental and global contexts. Concerning the format of the contest, Biennials call for regular reviews of a part of the architectural production supported by the recognition of its meaning. Among the varied ways of reward, the Biennials Grand Prix make it to these events almost in a consensual manner, being the maximum representatives of the architectural quality. In this context, this work represents a primary panorama over the top eleven Architecture Biennials in Latin America, in order to consolidate a characterization of these practices of architectural diffusion as a whole. In turn, the temporal cut of the last five Biennials that took place between 2005 and 2015, starting from the mapping of the winning buildings in these Biennials grand prix, will allow us some questionings that surround the nature of these maximum prizes within the scope of these architecture exhibitions. Within the numerous variables that surround the laureates, we will approach two specific cases of rewarded buildings, aiming for identifying and trying to understand what would be the existing relations between the oeuvre\'s speech and the jury\'s decision, in the specific context of each Biennial. Our effort, along this work, will be guided by the idea of the contemporary panorama of these Architecture Biennials as means of evaluation and diffusion of a part of the architectural production in harness with disciplinary practice.

As Bienais de Arquitetura constituem meios institucionalizados para a difusão e promoção das diferentes realizações da arquitetura em lugares onde essas práticas acontecem, consolidando, ao longo dos anos, uma arraigada tradição em vários países da América Latina, ao ponto de se tornarem importantes eventos de arquitetura no contexto nacional, continental e global. Sobre o formato do concurso, as Bienais convocam revisões periódicas de uma parte da produção arquitetônica amparadas pelo reconhecimento do mais significativo dela. Entre as diferentes formas de premiação, os Grandes Prêmios Bienais comparecem quase de maneira consensual nesses eventos, sendo os máximos representantes da qualidade arquitetônica. Nesse contexto, este trabalho apresenta um panorama preliminar sobre as onze Bienais de Arquitetura mais emblemáticas do cenário Latino-americano, a fim de consolidar uma caracterização dessas práticas de difusão arquitetônica como conjunto. Por sua vez, o recorte temporal das últimas cinco Bienais ocorridas entre 2005 e 2015, partindo do mapeamento das obras ganhadoras dos grandes prêmios dessas Bienais, permitirá trazer alguns questionamentos que envolvem a natureza desses máximos prêmios no âmbito dessas mostras de arquitetura. Dentro das diversas variáveis que envolvem os laureados, nos aproximaremos de dois casos particulares de obras premiadas, com o intuito de identificar e tentar entender quais seriam as relações existentes entre o discurso da obra e o laudo do Júri, no contexto particular de cada Bienal. O nosso esforço, ao longo deste trabalho, estará norteado pela ideia de panorama contemporâneo dessas Bienais de arquitetura, como formas de avaliação e difusão de uma parte da produção arquitetônica atreladas à pratica disciplinar. / Architecture Biennials organize institutionalized means for diffusion and promotion of varied architecture achievements in places where those practices happen, consolidating along the years an ingrained tradition in several Latin American countries to an extent of becoming important events of architecture in the national, continental and global contexts. Concerning the format of the contest, Biennials call for regular reviews of a part of the architectural production supported by the recognition of its meaning. Among the varied ways of reward, the Biennials Grand Prix make it to these events almost in a consensual manner, being the maximum representatives of the architectural quality. In this context, this work represents a primary panorama over the top eleven Architecture Biennials in Latin America, in order to consolidate a characterization of these practices of architectural diffusion as a whole. In turn, the temporal cut of the last five Biennials that took place between 2005 and 2015, starting from the mapping of the winning buildings in these Biennials grand prix, will allow us some questionings that surround the nature of these maximum prizes within the scope of these architecture exhibitions. Within the numerous variables that surround the laureates, we will approach two specific cases of rewarded buildings, aiming for identifying and trying to understand what would be the existing relations between the oeuvre\'s speech and the jury\'s decision, in the specific context of each Biennial. Our effort, along this work, will be guided by the idea of the contemporary panorama of these Architecture Biennials as means of evaluation and diffusion of a part of the architectural production in harness with disciplinary practice.

The ENSO-monsoon system is known to have a biennial component. Here we show using high resolution satellite data, mainly daily rainfall and sea surface temperature (SST) from the Tropical Rainfall Measuring Mission (TRMM), and daily scatterometer surface winds from QuickSCAT, that there is a clear biennial oscillation (TBO) in summer monsoon rainfall over Central India – Bay of Bengal (Cl-BoB) and the far west Pacific in the period 1999-2005. Summer (JJAS) mean rainfall oscillates between high and low values in alternate years; the rainfall is high in the odd years 1999, 2001, 2003, and 2005, and low in even years 2000, 2002 and 2004. The amplitude of the oscillation is significant, as measured against the long term standard deviation of seasonal rain based on 1979-2005 Global Precipitation Climatology Project (GPCP) data. We find that the TBO in rainfall is associated with TBO of SST over the tropical Indian, west Pacific and Atlantic Oceans in different seasons. There is no TBO in east Pacific SST, and no strong El Nino in this period. The TBO of SST is related to change in evaporation due to TBO of surface wind speed. A TBO of the surface branch of the Walker circulation in the eastern Indian and western Pacific basins is clearest in the autumn season during 1999-2005. There is a clear relation between a large-amplitude TBO of winter surface air temperature over north Asia associated with TBO of the Arctic oscillation (AO), and the TBO of summer monsoon rainfall. High rainfall over CI-BoB lin summer is followed by a relatively high value of the AO Index, and warm air termperature over north Asia in the succeeding winter. The Inter Tropical Convergence Zone(ITCZ) over the central Pacific and Atlantic Oceans shift north by about two degrees when the northern hemisphere is warm, reminiscent of the behaviour of the climate system of ENSO, decadal and palaeoclimate time scales. In this thesis we document the biennial oscillation of monsoon rain and its spatial structure in the recent period, and its relation with biennial oscillation of surface climate over the global tropics and extratropical regions. The existence of TBO in the tropical Atlantic, and its relation with the monsoon, is a new finding. We demonstrate that the interannual variability of the summer monsoon during 1999-2005, including the drought of 2002, is part of a pervasive TBO of global surface climate.

During the 1980s and 1990s, the world witnessed a radical change in which globalization diminished the power of the nation-state and shifted that impetus to a certain number of “Global Cities.” London, New York and Tokyo appeared to be the first of these cities and they acted as the heart of the new commercial and financial geography. In order to further strengthen their status, these cities organized transnational cultural events such as fairs, festivals and biennials.  Those events have been assumed as a driving force behind other political, economic and financial activities in the era of globalization. Since the 1980s, Istanbul has emerged as a candidate for a new global city at the eastern frontier of Europe. Thus, with the encouragement of the government, the private sector has begun to organize several large-scale cultural events in order to reshape the city as a global city and re-present the nation with a more European outlook. This is in keeping with the desire to facilitate Turkey’s EU accession process and attract global commercial activities. The Istanbul Biennial is one of the most important of these cultural initiatives. Thus, this research will scrutinize the Istanbul Biennial within this framework. The main premise will be: “The organization of the Istanbul Biennial aims to attract global financial activities, enable the political aspirations of the city and therefore transform the city into a global one.”

Essa dissertação discute a X Bienal de São Paulo, de 1969, buscando investigá-la dentro de uma conjuntura sociopolítica e cultural marcada pelas arbitrariedades de um regime ditatorial, pelas manifestações coletivas contrárias às injustiças, e pela tomada de uma consciência social por artistas e críticos de arte. O estudo procura, dessa forma, ampliar a discussão para além do boicote que atingiu a organização e realização da mostra. Por meio de uma extensa pesquisa dos documentos relativos ao assunto acumulados no Arquivo Histórico Wanda Svevo Fundação Bienal de São Paulo, foi possível juntar um material informativo que auxiliou na reconstrução dos fatos. Ao lado disso, para estabelecer uma análise crítica dos dados encontrados, recorreu-se aos relatos dos acontecimentos publicados na imprensa escrita da época e a uma bibliografia atualizada do campo da política, da sociologia, da história e da arte. A pesquisa apresenta os diversos ângulos de visão e atitude que permearam o boicote e a X Bienal inseridos no contexto efervescente do final da década de 1960. A mostra se concretizou marcada por contestações políticas e culturais e reverberou internamente os mesmo conflitos e contradições ideológicas do cenário macropolítico. Essa agitação teve como origem o impulso utópico por transformações radicais das estruturas conservadoras. / This essay examine the 10th São Paulo Biennial, from 1969, investigating it within a cultural and socio-political situation marked by arbitrariness of a dictatorship, the collective manifestations against injustices, and the social consciousness taking by artists and art critics. The study aims, therefore, broaden the discussion beyond the boycott that has reached the arrangements and the materialization of the show. By an extensive research of documents related to the subject accumulated at the Wanda Svevo Historical Archive - São Paulo Biennial Foundation, it was possible to collect a number of information that helped reconstructing the facts. Besides, to establish a critical analysis of the informational findings, it was restored the published press reports from that time and an updated bibliography of politics, sociology, history and art field. The research presents the different angles of vision and attitude that permeated the boycott and the 10th Biennial seething within the context of the late 1960s. The show was achieved marked by political and cultural challenges and reverberated inside the same conflicts and ideological contradictions of the macro-political scenario. This agitation had its origins in the utopian impulse looking for transformations of the conservative structures.

The Quasi-Biennial Oscillation (QBO) is the strongest phenomena influencing the stratopheric (~15-50 km height) circulation over the equator. QBO has two phases of downward propagating easterly and westerly winds, which has a total period of approximately 28 months and the phase is defined by the wind direction between the airpressure 25-50 hPa, which is roughly at a height of 30 km. QBO is induced by atmospheric gravity waves originating from the troposphere (~0-15 km height) and are generated by a plethora of sources, such as tropical convection and wind shear. The winds propagate downward at about 1 km per month through the stratosphere until reaching the tropopause (~15 km height) where they dissipate. The wind speed is at its maximum in the middle of the phase, where the wind shear is at its lowest, and the easterly winds can grow up to 30 m/s whilst the westerly winds reach roughly 15 m/s. Although the QBO is an equatorial phenomena it has a poleward component radiating its signal from the tropics to the higher latitudes where it affects other circulations such as the stratospheric polar vortex on the northern hemisphere (NH). The polar vortex consists of westerly winds around the polar region and is a major influence on the winter climate on the NH and thereby allows the QBO to indirectly affect the tropospheric climate through it. The easterly QBO disturbs and weakens the polar vortex, which results in warm subtropical air penetrating the vortex and warming the Arctic region whereas the polar air is released southward creating a colder winter on the NH. The westerly QBO on the other hand enhances the polar vortex and contains the cool polar air over the Arctic, which results in a milder winter. The correlation between QBO and El Niño Southern Oscillation (ENSO) as well as the tropical cyclones (TC) has either changed (ENSO) or completely disappeared (TC). The ENSO-QBO correlation depends on which phase of ENSO coincide with which phase of QBO, where El Niño coinciding with easterly QBO and La Niña coinciding with westerly QBO results in wind anomalies in the NH stratosphere. If the opposite combination takes place the wind anomalies will instead be situated in the subtropical troposphere, displacing the subtropical jet poleward. To what extent these stratospheric winds exert their influence is to some degree still uncertain, but that they have an effect on the tropospheric climate is unbeknownst to no one. / Cirkulationen i den ekvatoriella stratosfären (ca 15-50 km höjd) domineras av Quasi-Biennial Oscillation (QBO), ett zonalt (parallellt ekvatorn) vindfenomen med två faser bestående av östliga respektive västliga vindar och en period på ca 28 månader. Fasen definieras mellan lufttrycken 25-50 hPa, vilket representerar en höjd på ca 30 km. Drivkraften bakom QBO är ett brett spektrum av atmosfäriska gravitationsvågor som skapas genom bland annat den tropiska konvektionen, vindskjuvning och frontsystem. Vindarna propagerar vertikalt nedåt genom stratosfären med ungefär 1 km per månad tills de når tropopausen (ca 15 km) där vindarna försvagas kraftigt till ett zonalt medelvärde på 0 m/s. Vindhastigheten under östlig QBO uppgår i ca 30 m/s medan västlig QBO uppgår i ca 15 m/s, och är maximal i höga stratosfären samt i mitten av faserna där vindskjuvningen är minimal. QBO sprider sig meridionalt (nord-syd) från tropikerna till högre breddgrader genom stratosfären där andra fenomen som den stratosfäriska polarvirveln kan påverkas på norra halvklotet (NH). Polarvirveln består av västliga vindar i stratosfären runt polarregionen och är en stor influens på vinterklimatet i framförallt Europa och Nordamerika. Genom polarvirveln kan QBO indirekt påverka klimatet i troposfären (ca 0-15 km), där den östliga fasen av QBO försvagar medan den västliga fasen av QBO förstärker polarvirveln. En försvagad polarvirvel innebär en varmare medeltemperatur på Arktis och att kallare polarluft söker sig söderut och orsakar kalla vintertemperaturer. Troposfäriska klimatfenomen som El Niño Southern Oscillation (ENSO) och tropiska cykloner (TC) har uppvisat ett samband till QBO, men sedan förändrats (ENSO) eller helt försvunnit (TC). ENSO-QBO korrelationen förändras beroende på vilken fas QBO respektive ENSO är i relativt varandra. Då El Niño sammanfaller med östliga QBO samt La Niña sammanfaller med västliga QBO uppstår vindanomalier vid höga latituder i NH:s stratosfär, medan vid omvända sambandet förflyttar sig vindanomalierna till subtropikerna i troposfären och kan där förskjuta den subtropiska jetströmmen norrut. Att de stratosfäriska vindarna påverkar troposfären är känt, men hur och till vilken grad är ännu inte uppenbart. På grund av den korta tidsperiod med kontinuerliga och tillförlitliga vindmätningar i stratosfären uppkommer flera hypotetiska effekter av QBO och dess påverkan på klimatet i troposfären.