The phenomenon of a total solar eclipse has captivated human beings for millennium, often stirring a unique spiritual experience within its viewers. Witnesses claim to be intensely moved by the occurrence, and many contemporary “eclipse chasers” constantly travel across the globe to engulf themselves in the euphoric moments of totality. Before the advent of modern technology, both lunar and solar eclipses alike were quite terrifying, as they occurred unexpectedly and without warning. Eclipses induced fear rather than awe and wonder. Now that we possess the equipment to accurately track the Moon, Sun, and Earth, astronomers can pinpoint past eclipses as well as predict them far into the future. In fact, this practice has become so accurate that the date of Christ’s Crucifixion is estimated to have fallen on Friday, April 3, 33 AD1. Now that frightfulness has been removed from the equation, eclipses stand to provide an awe-inspiring as well as unifying experience. Just recently, the United States buzzed with collective anticipation; the total solar eclipse of August 21, 2017 cast a deep shadow from coast to coast2. Even those not the in the path of totality took time out of their day to witness a partial eclipse. Schoolchildren and adults alike came together to see these three celestial bodies align with magnificence. While a solar eclipse is a beautiful occurrence, spectators must take precautions to prevent permanent eye damage or blindness. The younger portion of the population is likely to have never experienced such a thing, thus there is a clear demand for education on safe eclipse viewing practices3. In reconciling the unique psychological effects, physical limitations, and dangers associated with watching a solar eclipse, architecture as a collection of geographical and spatial resources will offer a unique setting for eclipse anticipation and totality. The challenge to such a proposal lies in the paradoxical frequency of solar eclipses. A physical response thus requires a combination of mobile and stationary elements. Temporary vessels will be deployed in several locations as the schedule of future eclipses unfolds. Static structures and inscriptions scored into the earth serve as a memorial to the fleeting event, allowing the architecture to educate beyond the lifespan of the eclipse. These interventions serve to impress upon the occupant the enormity of such a celestial alignment. / 0 / SPK / archives@tulane.edu

The entire contiguous United States experienced a solar eclipse on August 21st, 2017 which passed from the Pacific to the Atlantic Coasts. The path of totality crossed 14 states while other states had partial eclipse. Due to the rarity of this event, it was known as “The Great American Eclipse” and NASA collaborated with 52 universities across the United States to launch weather balloon payloads to record this impactful event. Although Montana State University designed a workshop for all universities involved in order to assist those not experienced in the area, Mississippi State University decided to design our own payload. Our system was designed in order to meet the standards of a 2U CubeSat. One key aspect of our payload is that it is entirely made from 3D printed parts with over 100 prototype parts made over the length of two years. Instead of buying an off the shelf flight computer, we designed and built a custom Hexa-Processor Computer Board which gave us flexibility with the computation needs. A turret was also developed that housed two cameras and could spin 360 degrees, allowing it to counter act the rotations of the payload in order to obtain a stabilized image. The payload was launched in Kentucky and was a successful flight without any damages to the payload.

The ionosphere is a constantly changing medium. From the sun to cosmic rays, the ionosphere proves to be a continually interesting area of study. The most notable change that occurs in the ionosphere is the day and night cycle. The ionosphere is not a singular medium, but rather made up of different sections. The day side of the ionosphere consists of a D, E, F1, and F2 layer. The night day of the ionosphere consists of an E and F layer. These layers all have different properties and characteristics associated with them. A notable interaction is how radio waves propagate through the ionosphere. A radio wave can either reflect, refract, or pass through a layer of the ionosphere depending on the frequency of the signal, among other sources of disturbance. The ability to have a radio wave reflected back downwards is a core principle of an ionosonde, which measures the height of the ionosphere. A solar eclipse presents a night side ionosphere condition during the day. The change in the ionosphere that the eclipse will cause is something not a lot of research has gone into. This thesis aims to elaborate on the design and development of an ionosonde along with eventual ionosphere readings during the August 2017 total solar eclipse. / Master of Science / The atmosphere that surrounds the earth is made up of various unique regions. The region of interest for this thesis is the ionosphere. The ionosphere plays an important role in wireless communication of radio waves. It follows that changes in the ionosphere are something of great interest and study. A notable change that the ionosphere undergoes on a daily basis is the shift from the day side to the night side. A solar eclipse serves not only as a spectacular sight, but also to bring a night side condition to the day side. This thesis aims to uncover the changes that will occur to the ionosphere during the August 2017 total solar eclipse.

Während der Sonnenfinsternis am 11. 8. 1999 kam es zu einer kurzzeitigen starken Abnahme der Ionisation im Höhenbereich der D-Region (60-90 km Höhe) am Unterrand der Ionosphäre. Mit bodengebundenen funktechnischen Beobachtungen der Ausbreitung elektromagnetischer Wellen über die D-Region konnte dieses Ereignis in charakteristischer Weise als ein simulierter Tag-Nacht-Übergang mit allen zu erwartenden Konsequenzen beobachtet werden. Auf der Basis von Funkwellen-Ausbreitungsmessungen werden in Collm (51.3°N, 13°E) Windmessungen im Höhenbereich der Mesopause und unteren Thermosphäre (80-105 km) durchgeführt, die in der Regel - bedingt durch die Besonderheiten der ionosphärischen Wellenausbreitung des verwendeten Frequenzbereiches - nur in den Nachtstunden möglich sind. Während der Hauptphase des Finsterniseffektes wurden Messungen auch am Tag möglich. Die Ergebnisse fügen sich gut in das aus den mittleren monatlichen Nachtwerten für die Tagstunden extrapolierte Niveau ein. Die Reaktion der Ionosphäre auf die Sonnenfinsternis erfolgte mit geringer Verzögerung: der maximale Effekt war 5-10 Minuten nach der größten Abdeckung der Sonnenscheibe zu verzeichnen. / During the solar eclipse on 11 August 1999 a short-term decrease of ionisation in the D-region ( 60- 90 km altitude) at the lower boundary of the ionosphere appeared. Using ground-based measurements of radio-wave propagation through the D-region the event could be monitored as a simulated day-night-transition with the expected consequences for the ionosphere. At Collm (51.3°N, 13°E), mesopause region (80-105 km) windmeasurements are carried out based on radio wave propagation, which are not possible in summer during daylight hours due to radio-wave absorption. During the eclipse measurements became possible for a short period. Tue results fit well to mean monthly daytime data extrapolated from nighttime measurements. The reaction of the ionosphere on the solar eclipse was fast; the maximum effect was registered only 5-10 minutes after the maximum eclipse of the solar disk.

My artistic practice creates relationships between the abstract and the personal. I define the abstract in the context of my studio work as a material exploration of color and form. The personal encompasses autobiography in relation to my sense of time and place. In this text, I use my concept of oceanic tides (considered as a temporal and spatial shift between states) to chart my activities as an artist. These activities include making objects that change in character over time, and durational work including performance and video. Interwoven throughout Tides are narrative passages based on my personal experiences, including witnessing the total eclipse of the sun, a purple garden, a coincidence, and the death of a friend.

A full solar eclipse is going to be visible from a range of states in the contiguous United States on August 21, 2017. Since the atmosphere of the Earth is charged by the sun, the blocking of the sunlight by the moon may cause short term changes to the atmosphere, such as density and temperature alterations. There are many ways to measure these changes, one of these being ionospheric scintillation. Ionospheric scintillation is rapid amplitude and phase fluctuations of signals passing through the ionosphere caused by electron density irregularities in the ionosphere. At mid-latitudes, scintillation is not as common of an occurrence as it is in equatorial or high-altitude regions. One of the theories that this paper looks into is the possibility of the solar eclipse producing an instability in the ionosphere that will cause the mid-latitude region to experience scintillations that would not normally be present. Instabilities that could produce scintillation are reviewed and altered further to model similar conditions to those that might occur during the solar eclipse. From this, the satellites that are being used are discuses, as is hardware and software tools were developed to record the scintillation measurements. Although this work was accomplished before the eclipse occurred, measurement tools were developed and verified along with generating a model that predicted if the solar eclipse will produce an instability large enough to cause scintillation for high frequency satellite downlinks. / Master of Science

Während der Sonnenfinsternis am 11. 8. 1999 kam es zu einer kurzzeitigen starken Abnahme der Ionisation im Höhenbereich der D-Region (60-90 km Höhe) am Unterrand der Ionosphäre. Mit bodengebundenen funktechnischen Beobachtungen der Ausbreitung elektromagnetischer Wellen über die D-Region konnte dieses Ereignis in charakteristischer Weise als ein simulierter Tag-Nacht-Übergang mit allen zu erwartenden Konsequenzen beobachtet werden. Auf der Basis von Funkwellen-Ausbreitungsmessungen werden in Collm (51.3°N, 13°E) Windmessungen im Höhenbereich der Mesopause und unteren Thermosphäre (80-105 km) durchgeführt, die in der Regel - bedingt durch die Besonderheiten der ionosphärischen Wellenausbreitung des verwendeten Frequenzbereiches - nur in den Nachtstunden möglich sind. Während der Hauptphase des Finsterniseffektes wurden Messungen auch am Tag möglich. Die Ergebnisse fügen sich gut in das aus den mittleren monatlichen Nachtwerten für die Tagstunden extrapolierte Niveau ein. Die Reaktion der Ionosphäre auf die Sonnenfinsternis erfolgte mit geringer Verzögerung: der maximale Effekt war 5-10 Minuten nach der größten Abdeckung der Sonnenscheibe zu verzeichnen. / During the solar eclipse on 11 August 1999 a short-term decrease of ionisation in the D-region ( 60- 90 km altitude) at the lower boundary of the ionosphere appeared. Using ground-based measurements of radio-wave propagation through the D-region the event could be monitored as a simulated day-night-transition with the expected consequences for the ionosphere. At Collm (51.3°N, 13°E), mesopause region (80-105 km) windmeasurements are carried out based on radio wave propagation, which are not possible in summer during daylight hours due to radio-wave absorption. During the eclipse measurements became possible for a short period. Tue results fit well to mean monthly daytime data extrapolated from nighttime measurements. The reaction of the ionosphere on the solar eclipse was fast; the maximum effect was registered only 5-10 minutes after the maximum eclipse of the solar disk.

Made available in DSpace on 2016-03-15T19:38:53Z (GMT). No. of bitstreams: 1 ALBERTO FARES AKEL JUNIOR.pdf: 5112998 bytes, checksum: f18fc33d2f9508c3ec265c0efa016b43 (MD5) Previous issue date: 2015-08-21 / Fundação de Amparo a Pesquisa do Estado de São Paulo / We study the behavior of the Earth-ionosphere waveguide through the modeling of the propagation of very low frequency radio waves (VLF). We use the computational model LWPC (Long Wave Propagation Capability) to estimate changes in amplitude and phase of the VLF signals detected by the SAVNET network (South America VLF NETwork), and thus try to understand the behavior of the lower ionosphere under different ionization conditions. The research was divided into two parts. The first part investigates the behavior of the VLF signals in quiescent regimes of ionization. Amplitude and phase simulations for the were carried out, modifying adapting polynomials for the β and h parameters (or Wait s parameters) as a function of the zenithal angle. The second part of this research, uses these polynomials in the study of the lower ionosphere under transient ionization regimes in two distinct conditions: first during of solar flares and second during solar eclipse. For the simulations under solar flare conditions, we calculate the changes in β and ℎ′ parameters during the 25/03/2008 solar explosion. With these values, we calculate the electronic density profile through an exponential model and we find that the electronic density at 75 km is ∼ 104 cm−3, that is twenty times higher than during quiescent conditions. To evaluate our parameter estimates, we calculate the variation of the Wait s parameters for the case of twelve solar events of different classes. We note that the variations Δℎ′ found in this work are larger than that in Muraoka, Murata e Sato (1977) because they consider the variations in the conductivity gradient. For the solar eclipse simulations on 11/07/2011, we investigate its effect on the VLF phase. For this, we use the obscuration coefficient to estimate the guide height variation along the whole path during the eclipse. The simulations reproduce the phase behavior during the eclipse. However, a delay of about twenty four minutes was observed between the simulated and observed measurements. The observed delay is a direct consequence of own estimates of the perturbed ionospheric height and it causal relation with the obscuration during the eclipse. lower ionosphere, VLF, modeling, ionospheric disturbances, solar flares, solar eclipse. / Neste trabalho realizamos o estudo do comportamento do guia de ondas terra-ionosfera através da modelagem da propagação ondas de rádio de frequência muito baixa (VLF). Para isto, utilizamos o modelo computacional LWPC (Long Wave Propagation Capability) para estimar as variações de amplitude e fase de sinais de VLF detectados nos trajetos da rede SAVNET (South America VLF NETwork) e assim compreender o comportamento da baixa ionosfera em diferentes regimes de ionização. A pesquisa foi dividida em duas partes. A primeira parte, investigou o comportamento do sinal VLF em regimes quiescente de ionização, assim realizou-se simulações de amplitude e fase adaptando polinômios que definem os parâmetros β e ℎ′ (ou parâmetros de Wait) em função do ângulo zenital solar. Na segunda parte desta pesquisa, aplicou-se os polinômios no estudo da baixa ionosfera sob regimes transientes de ionização em duas condições distintas. A primeira para o caso de explosões solares e a segunda um para eclipse solar. Nas simulações relativas a explosões solares, calculamos as variações dos parâmetros β e ℎ′ durante o evento do dia 25/03/2008. Com esses valores, calculamos o perfil de densidade eletrônica, através de um modelo exponencial e observamos que a densidade eletrônica em 75 km é ∼ 104 cm−3, ou seja, vinte vezes maiores que antes da explosão. Para avaliar nossas estimativas, calculamos a variação dos parâmetros de Wait para doze eventos de diferentes classes. Observamos que as variações Δℎ′ neste trabalho são sempre maiores do que as descritas em Muraoka, Murata e Sato (1977), devido elas considerarem as variações no gradiente de condutividade. Nas simulações relativa ao eclipse solar do dia 11/07/2011, investigamos seu efeito na fase observada. Para esse estudo, utilizou-se o coeficiente de obscurecimento para realizar as simulações, desta forma foi possível estimar a variação da altura do guia ao longo de todo o trajeto durante o eclipse. As simulações reproduziram o comportamento da fase durante o eclipse. Entretanto, foi observado um atraso entre as medidas calculadas e observadas de aproximadamente ∼ vinte e quatro minutos. O atraso observado é diretamente decorrente da estimativa da altura de referência da ionosfera pertubada e de sua relação causal com o obscurecimento durante o eclipse.

Made available in DSpace on 2016-03-15T19:35:52Z (GMT). No. of bitstreams: 1 JOSE CARLOS TACZA ANAYA.pdf: 7682166 bytes, checksum: f3eebed2cf5cb0f5ecda9415f8754978 (MD5) Previous issue date: 2015-01-19 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / In this dissertation, we present the capability of a new network of sensors to monitor the atmospheric electric field at various locations in South America. The main goal is to obtain the characteristic Universal Time daily curve of the atmospheric electric field in fair-weather. That curve is known as the Carnegie curve, which is related to the currents flowing in the Global Atmospheric Electric Circuit. This has been accomplished using monthly, seasonal and annual averages. After obtaining our standard curve of variation of the electric field in fair-weather, the deviations related to phenomena such as solar flares, solar protons events, geomagnetic storms, total solar eclipse and seismic activity are analyzed and commented. / Neste trabalho de dissertação apresenta-se a capabilidade de uma nova rede de sensores para monitorar o campo elétrico atmosférico em vários locais na América do Sul. O objetivo principal é obter a curva diária do campo elétrico atmosférico de tempo bom. Para isto foram realizadas médias mensais, sazonais e anuais. Essa curva é comparada com a curva característica em Tempo Universal conhecida como a Curva de Carnegie, a qual é relacionada com as correntes fluindo no Circuito Elétrico Atmosférico Global. Depois de obter a curva padrão de variação do campo elétrico atmosférico de tempo bom, foram analisados e comentados os desvios relacionados a explosões solares, eventos de prótons solares, tempestades geomagnéticas, eclipse solar e atividade sísmica.