Operationelle in-situ Messungen von Luftschadstoffen und Klimagasen im nationalen und internationalen Kontext

<p>Im Unterschied zu Forschungsinfrastrukturen in anderen Disziplinen, zeichnen sich Forschungsinfrastrukturen für Umweltbeobachtungen in der Regel durch langfristige Messungen zahlreicher Parameter mit verschiedenen Instrumenten an unterschiedlichen Orten aus. Bodengestützte, atmosphärische Beobachtungen von Luftschadstoffen und Klimagasen können unterschiedliche Ziele verfolgen, wie zum Beispiel die Überwachung regulatorischer Massnahmen und die Einhaltung von Grenzwerten, die wissenschaftliche Untersuchung von Variabilitäten und Trends, die Validierung von Modellrechnungen und Satellitenbeobachtungen oder die Früherkennung von neu auftretenden Substanzen. Die Qualitätskontrolle und Qualitätssicherung müssen nicht nur dem dezentralen Charakter der Beobachtungen Rechnung tragen, sondern auch sicherstellen, dass die der Fragestellung angepassten Datenqualitätsziele erreicht werden. Zusätzlich müssen Beobachtungen, die Teil von mehreren Messnetzen und Infrastrukturen sind, verschiedene Kriterien erfüllen, z.B. im Hinblick auf das Normal der Rückführbarkeit, die Präzision, aber auch bezüglich Dokumentation und Bereitstellung der Resultate in Datenbanken.</p> <p>Die Präsentation gibt einen Überblick über die langfristigen Luftqualitätsmessungen in der Schweiz im Rahmen des Nationalen Beobachtungsnetzes für Luftfremdstoffe (NABEL), ihre Einbettung in das European Monitoring and Evaluation Programme (EMEP), die Kooperation mit den europäischen Forschungsinfrastrukturen ICOS (Integrated Carbon Observation System) und ACTRIS (Aerosols, Clouds, and Trace gases Research Infrastructure Network), und die Zusammenarbeit in globalen Aktivitäten wie dem Advanced Global Atmospheric Gases Experiment (AGAGE) zur kontinuierlichen Messung von klimawirksamen und ozonabbauenden Substanzen und dem von der Weltorganisation für Meteorologie (WMO) koordinierten Global Atmosphere Watch (GAW) Programm.</p>

Fixing Subjects, Fixing Outcomes: Civic Epistemologies and Epistemic Agency in Participatory Governance of Climate Risk

Participatory forms of policy-making have often been criticized for insufficiently theorizing the coproduction of publics and matters of concern. This paper seeks to investigate this relationship further by analyzing how the concept of civic epistemologies (CEs) can provide insights for understanding how political contexts shape both publics and contestable debates. Presenting fieldwork on cyclone governance in Odisha, India, based on the analysis of interviews with vulnerable fishing communities and state actors, the article shows how CEs influence the interdependent formation of vulnerable fisher and state subjectivities on one hand with representations of risk located in external biophysical atmospheric gases on the other, thereby sustaining reductive roles and futures. At the same time, the paper develops the concept of CEs by examining them as performative acts carried out by marginalized communities and state actors at the subnational level of a nonindustrialized country, thereby indicating sites at which epistemic agency can be increased and governed. Participatory knowledge production needs to understand how it is affected by CEs if it is to generate effective expertise for transformative futures in the face of increasing climatic risks.

ESTIMATION DE LA VISIBILITÉ MÉTÉOROLOGIQUE À L’AIDE DES LIENS MICRO-ONDES COMMERCIAUX DE TÉLÉCOMMUNICATIONS

Several factors can attenuate radio signal between transmitting and receiving antenna. One can cite: vegetation, atmospheric gases, fog, water vapor, transmission instruments, rain, temperature, etc... The sources of attenuation differ according to the climate and the relief of each continent or even each country. In this work we aim to show that there is link between microwave signal attenuation and weather visibility in the presence of dust. Weather visibility is a very important factor for the safety of road, sea, rail and air transportation. In the presence of dust, the visibility is strongly reduced and there is also a strong attenuation of the microwave signal propagating between two antennas. By performing a linear regression on the attenuation-visibility scatter plot, we propose a method for real-time estimation of the visibility knowing the microwave signals attenuation. A correlation measurement between the visibility estimated by our method from the real attenuation data of the mobile phone operator Telecel Faso SA (Burkina Faso) and the visibility measured by the National Meteorological Agency of Burkina Faso (ANAM) gave a correlation coefficient of 0.86.

Observing meteors by creating artificial luminous clouds in the Earth’s atmosphere

В статье дается предварительная теоретическая оценка возможности применения нового способа наблюдения метеоров в атмосфере Земли с помощью искусственных светящихся облаков. При попадании метеоров в такие облака, образованные веществом с потенциалом ионизации в несколько раз меньшем потенциала ионизации атмосферных газов, происходит быстрая ионизация реагента облака за счет термического и ударного воздействия метеорного тела, приводящая к увеличению светимости метеорных следов. Предполагается, что такой эффект будет способствовать увеличению яркости слабых метеоров, находящихся на пороге обнаружения современных телевизионных камер. Это позволит проводить исследования метеоров и метеорных потоков, доступных ранее только радиолокационными методами наблюдения. The article provides a preliminary theoretical assessment of the possibility of using a new method of observing meteors in the Earth’s atmosphere using artificial luminous clouds. When meteors hit such clouds formed by a substance with an ionization potential several times lower than the ionization potential of atmospheric gases, the cloud reagent is rapidly ionized due to the thermal and impact effects of the meteor body, which leads to an increase in the luminosity of meteor tracks. It is assumed that this effect will increase the brightness of weak meteors, which are on the threshold of detection by modern TV cameras. This will make it possible to conduct studies of meteors and meteor showers that were previously available only by radar observation methods.

The “ideal” spectrograph for atmospheric observations

Spectroscopy of scattered sunlight in the near-UV to near-IR spectral ranges has proven to be an extremely useful tool for the analysis of atmospheric trace gas distributions. A central parameter for the achievable sensitivity and spatial resolution of spectroscopic instruments is the étendue (product of aperture angle and entrance area) of the spectrograph, which is at the heart of the instrument. The étendue of an instrument can be enhanced by (1) upscaling all instrument dimensions or (2) by changing the instrument F number, (3) by increasing the entrance area, or (4) by operating many instruments (of identical design) in parallel. The étendue can be enhanced by (in principle) arbitrary factors by options (1) and (4); the effect of options (2) and (3) is limited. We present some new ideas and considerations of how instruments for the spectroscopic determination of atmospheric gases could be optimized using new possibilities in spectrograph design and manufacturing. Particular emphasis is on arrays of massively parallel instruments for observations using scattered sunlight. Such arrays can reduce size and weight of instruments by orders of magnitude while preserving spectral resolution and light throughput. We also discuss the optimal size of individual spectrographs in a spectrograph array and give examples of spectrograph systems for use on a (low Earth orbit) satellite, including one with sub-kilometre ground pixel size.

Scattering and absorption cross sections of atmospheric gases in the ultraviolet–visible wavelength range (307–725 nm)

Accurate Rayleigh scattering and absorption cross sections of atmospheric gases are essential for understanding the propagation of electromagnetic radiation in planetary atmospheres. Accurate extinction cross sections are also essential for calibrating high-finesse optical cavities and differential optical absorption spectroscopy and for accurate remote sensing. In this study, we measured the scattering and absorption cross sections of carbon dioxide, nitrous oxide, sulfur hexafluoride, oxygen, and methane in the continuous wavelength range of 307–725 nm using broadband cavity-enhanced spectroscopy (BBCES). The experimentally derived Rayleigh scattering cross sections for CO2, N2O, SF6, O2, and CH4 agree with refractive index-based calculations, with a difference of (0.4 ± 1.2) %, (−0.6 ± 1.1) %, (0.9 ± 1.4) %, (2.8 ± 1.2) %, and (0.9 ± 2.2) %, respectively. The O2–O2 collision-induced absorption and absorption by methane are obtained with high precision at the 0.8 nm resolution of our BBCES instrument in the 307–725 nm wavelength range. New dispersion relations for N2O, SF6, and CH4 were derived using data in the UV–vis wavelength range. This study provides dispersion relations for refractive indices, n-based Rayleigh scattering cross sections, and absorption cross sections based on more continuous and more extended wavelength ranges than available in the current literature.

Effect of toxic gases on human erythrocytes: Spectrophotometric analysis.

Objective: This study was carried out to analyze the influence of various toxic gases on human erythrocytes. Study Design: Experimental study. Setting: Department of Chemistry, Hazara University, Mansehra. Period: January 2017 to June 2017. Material & Methods: Erythrocytes were isolated and prepared by the standard method from blood samples. The standard absorption spectra were recorded in the range of 200-800nm using double‐beam UV‐visible spectrophotometer. Gases were prepared in laboratory as per given protocol. Erythrocyte samples were treated with prepared gases. Absorbance of the samples was recorded. The spectrum of these treated samples was compared with the standard spectra of erythrocytes to check for any changes that might have occurred. Results: It was observed that erythrocytes exhibiteded altered behavior with each gas which was confirmed by shift in peaks in UV/Visible spectra. Absorption maxima were shifted from higher to lower wavelengths and this shift was more pronounced in case of Chlorine, Carbon Monoxide and Carbon Dioxide as compared to that observed in case of Hydrogen Sulfide, Sulfur dioxide, and Nitrogen Dioxide. Conclusion: This study showed that erythrocytes exhibit different behavior with different gases as evident by the shift of peaks in UV/Visible spectra. The absorption maxima were shifted towards lower wavelengths suggesting that these gases do exert an effect on human erythrocytes. The lipid site of erythrocytes, being sensitive for absorbing various atmospheric gases, caused deformation of original erythrocyte structure and altered their activity. This type of interaction of red blood cells with such external species, particularly the donor-acceptor case, caused damage to erythrocytes and in turn, decreased their number.