New observation strategies for the solar UV spectral irradiance

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In the frame of the JUICE mission, preliminary studies of the Jupiter's icy moons, such as Ganymede and Europa, are mandatory. The present paper aims at characterizing the impact of the solar UV flux and its variability on their atmospheres. The solar UV radiation is responsible for the photoionization, photodissociation, and photoexcitation processes within planetary atmospheres. A 1-D photoabsorption model has been developed for different observational geometries, on the basis of a neutral atmospheric model. Considering various production and loss mechanisms but also the transport of oxygen atoms, we estimate the red and green line emissions from photo impact-induced excitation only. These dayglow emissions can represent few percent of the global airglow emission, mainly dominated by electron-induced excitation in auroral regions. For limb viewing conditions, red line emission is bright enough to be detected from actual spectrometers, from 338 R to 408 R according to the solar activity. This is also the case for the green line with 8 R at limb viewing. Considering a different neutral atmosphere model, with an O 2 column density 50% more important, leads to a 14% increase in the red line emissions for limb viewing close to the surface. This difference could be important enough to infer which neutral model is the most likely. However, uncertainties on the solar UV flux might also prevent to constrain the O 2 column density when using ground-based observations in the visible only. The impact of solar flares on the red line emissions for Europa has also been investigated within a planetary space weather context.

Section: Modeling Using Reference Spectramentioning

confidence: 99%

Photochemistry-emission coupled model for Europa and Ganymede

Cessateur

Barthélemy

Peinke

2016

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“…Recently, high-quality CBN, AlN, and diamond metal-semiconductor-metal (MSM) photodetectors have been tested for EUV-UV measurements (BenMoussa et al 2009). In the frame of solar UV irradiance monitoring, Cessateur et al (2012) recently investigated the possibility to use such new wide-band gap materials to reconstruct the solar UV spectrum. Using different detector architectures and different materials without upstream filters (which are one of the main causes of degradation), key spectral ranges for reconstructing the variability of the spectral irradiance in the UV have been identified.…”

Section: Solar Irradiance Variability/spectrum Versus the Solar Activitymentioning

confidence: 99%

Solar activity and its evolution across the corona: recent advances

Zuccarello¹,

Balmaceda

Cessateur

et al. 2013

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Solar magnetism is responsible for the several active phenomena that occur in the solar atmosphere. The consequences of these phenomena on the solar-terrestrial environment and on Space Weather are nowadays clearly recognized, even if not yet fully understood. In order to shed light on the mechanisms that are at the basis of the Space Weather, it is necessary to investigate the sequence of phenomena starting in the solar atmosphere and developing across the outer layers of the Sun and along the path from the Sun to the Earth. This goal can be reached by a combined multi-disciplinary, multi-instrument, multi-wavelength study of these phenomena, starting with the very first manifestation of solar active region formation and evolution, followed by explosive phenomena (i.e., flares, erupting prominences, coronal mass ejections), and ending with the interaction of plasma magnetized clouds expelled from the Sun with the interplanetary magnetic field and medium. This wide field of research constitutes one of the main aims of COST Action ES0803: Developing Space Weather products and services in Europe. In particular, one of the tasks of this COST Action was to investigate the Progress in Scientific Understanding of Space Weather. In this paper we review the state of the art of our comprehension of some phenomena that, in the scenario outlined above, might have a role on Space Weather, focusing on the researches, thematic reviews, and main results obtained during the COST Action ES0803.

“…SOTERIA deployed also a considerable effort in utilising and developing theoretical and simulation models for interpreting the space weather data, covering all aspects of the complex Sun-Earth connection. SOTERIA also provided guidance for future investigations as manifested in the article ''New observation strategies for the solar UV spectral irradiance'' by Cessateur et al (2012).…”

Section: Global Modellingmentioning

confidence: 99%

Space weather in the EU’s FP7 Space Theme

Chiarini

2013

Technological infrastructures in space and on ground provide services on which modern society and economies rely. Space weather related research is funded under the 7th Framework Programme for Research and Innovation (FP7) of the European Union in response to the need of protecting such critical infrastructures from the damage which could be caused by extreme space weather events. The calls for proposals published under the topic ''Security of space assets from space weather events'' of the FP7 Space Theme aimed to improve forecasts and predictions of disruptive space weather events as well as identify best practices to limit the impacts on space-and ground-based infrastructures and their data provision. Space weather related work was also funded under the topic ''Exploitation of space science and exploration data'', which aims to add value to space missions and Earth-based observations by contributing to the effective scientific exploitation of collected data. Since 2007 a total of 20 collaborative projects have been funded, covering a variety of physical phenomena associated with space weather, from ionospheric disturbances and scintillation, to geomagnetically induced currents at Earth's surface, to coronal mass ejections and solar energetic particles. This article provides an overview of the funded projects, touching upon some results and referring to specific websites for a more exhaustive description of the projects' outcomes.