Breeding Forages to Cope with Environmental Challenges in the Light of Climate Change and Resource Limitations.

Projected climate change and increased pressure for adopting more sustainable agricultural practices calls for new approaches in breeding forage crops for the future. In the cool temperate regions of Europe they may benefit from a warmer and prolonged growing season, even though new stresses may emerge during autumn and winter, whereas further south risk of drought will increase. In addition, forage crops have to be able to use both nutrients and water more efficiently in the future in order to maximize production per unit area. Examples are given how perennial forage crops can be adapted to the projected envi-ronmental conditions in Europe through breeding. In the Nordic region the focus is on identifying traits that are important for high yields under changed overwin-tering conditions, as well as management practices. In maritime, oceanic Europe the focus is on forage grass and legume root systems for ecosystem service, nutri-ent and water use, and the advantages and potential for Festulolium, including its role in ruminant nutrition. In temperate and southern Europe, the aim is to develop varieties able to survive long drought periods and to recover rapidly following autumn rains, as well as improving adapted legume species to reduce the use of synthetic fertilizers, the environmental impacts of ruminant production systems and their dependency on external protein-rich feeds. Forage production systems, commonly found in areas less suited to grain production, can contribute significantly to future food security if the adaptation of forage crops to the future environmental challenges is successful

Probing Jupiter’s auroral radio sources with Juno

Jupiter is the major auroral radio source in our solar system, producing Jovian low-frequency radio emissions in a broad frequency range of 10 kHz to 40 MHz from both north and south polar regions of the planet. These sporadic nonthermal bursts have been monitored with the radio and plasma wave instrument (Waves) aboard the spinning Juno spacecraft in polar orbit about Jupiter since July 5, 2016. The Waves instrument is composed of one electric dipole antenna, one magnetic search coil sensor, and three on-board receivers that record the electric fields of waves from 50 Hz to 41 MHz and the magnetic fields of waves from 50 Hz to 20 kHz. Juno has three advantageous methods to determine the radio source locations and the beaming properties for the Jovian low-frequency radio emissions: (1) identifying emission frequency close to the local gyrofrequency at the source with in situ particle measurements through Juno's perijove surveys from pole to pole, (2) the spin-modulated spectral density recorded with Juno Waves to estimate the direction of arrival of incoming waves, and (3) with the aid of the Jovian radio beaming model, performing stereoscopic radio observations with Juno, Cassini, STEREO A, WIND, and Earth-based radio telescopes (e.g., LWA1 in New Mexico, USA, and NDA in Nançay, France) or investigating the statistical characteristics of Jovian radio occurrence by Juno. Because the three individual methods are self-consistent and complement each other, Juno observations are useful for determining the Jovian radio beam parameters and radio source locations, which can be traced along magnetic field lines onto Jupiter's atmosphere and further compared with the UV aurora taken by the Hubble Space Telescope. In this talk, we give a brief overview of early radio astronomy results from Juno, providing the recent results from these extended studies by means of the three methods

A PRELIMINARY STUDY OF MIT COUPLING AT JUPITER BASED ON JUNO OBSERVATIONS AND MODELLING TOOLS

The dynamics of the Jovian magnetosphere is controlled by the complex in- terplay of the planet’s fast rotation, its solar-wind interaction and its main plasma source at the Io torus. Juno observations have amply demonstrated that the Magnetosphere-Ionosphere-Thermosphere (MIT) coupling process- es and regimes which control this interplay are significantly different from their Earth and Saturn counterparts. At the ionospheric level, these MIT cou- pling processes can be characterized by a set of key parameters which in- clude ionospheric electrodynamic parameters (conductances, currents and electric fields), exchanges of particles along field lines and auroral emissions. Knowledge of these key parameters in turn makes it possible to estimate the net deposition/extraction of momentum and energy into/out of the Jovian upper atmosphere. We will present a method combining Juno multi-instru- ment data (MAG, JADE, JEDI, UVS, JIRAM and WAVES), adequate modelling tools (the TRANSPLANET ionospheric dynamics model and a simplified set of ionospheric current closure equations) and the AMDA data handling tools to provide preliminary estimates of these key parameters and their variation along the ionospheric footprint of Juno’s magnetic field line and across the auroral ovals for three of the first perijoves of the mission. We will discuss how this synergistic use of data and models can also contribute to provide a better determination of poorly known parameters such as the vertical struc- ture of the auroral and polar Jovian neutral atmosphere

The Cluster Spatio-Temporal Analysis of Field Fluctuations (STAFF) Experiment

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First results obtained by the Cluster STAFF experiment

International audienceThe Spatio Temporal Analysis of Field Fluctuations (STAFF) experiment is one of the five experiments, which constitute the Cluster Wave Experiment Consortium (WEC). STAFF consists of a three-axis search coil magnetometer to measure magnetic fluctuations at frequencies up to 4 kHz, a waveform unit (up to either 10 Hz or 180 Hz) and a Spectrum Analyser (up to 4 kHz). The Spectrum Analyser combines the 3 magnetic components of the waves with the two electric components measured by the Electric Fields and Waves experiment (EFW) to calculate in real time the 5 × 5 Hermitian cross-spectral matrix at 27 frequencies distributed logarithmically in the frequency range 8 Hz to 4 kHz. The time resolution varies between 0.125 s and 4 s. The first results show the capabilities of the experiment, with examples in different regions of the magnetosphere-solar wind system that were encountered by Cluster at the beginning of its operational phase. First results obtained by the use of some of the tools that have been prepared specifically for the Cluster mission are described. The characterisation of the motion of the bow shock between successive crossings, using the reciprocal vector method, is given. The full characterisation of the waves analysed by the Spectrum Analyser, thanks to a dedicated program called PRASSADCO, is applied to some events; in particular a case of very confined electromagnetic waves in the vicinity of the equatorial region is presented and discussed