The Sun often produces eruptive events on different energetic and temporal scales. It might, however, also produce events, so-called extreme solar events, whose energy could be orders of magnitude greater than anything we have observed during recent decades. But what is an extreme solar event? How strong can they be and how often do they occur?
The dynamic connections between space weather and weather in Earth’s lower atmosphere was the target of last week’s ISSI workshop. This gathering, between leading experts in space, Earth observation and atmospheric science, delved into the intricate physical interplay shaping our planet’s weather and climate.
Extreme geomagnetic storms can have significant impact on a wide range of technologies and a particular challenge is quantifying their occurrence likelihood since they are rare events. Geomagnetic storm occurrence varies with the solar cycle and each cycle has a unique amplitude and duration. Whilst there are comprehensive high fidelity space weather relevant observations over the last four to five solar cycles, observations that extend over multiple cycles are more limited. Nevertheless, historical ground magnetic observations over the last 150 years can be used to quantify space weather risk. They can be combined with the sunspot record to construct a uniform ‘clock’ for space weather activity which reveals a fast switch-on (and off) between the relatively quiet conditions around solar minima, and more active conditions around solar maxima. The clock provides a framework to predict the switch-on and off times, imperative since some of the most extreme events have occurred just after the switch-on.
In the last few years machine learning techniques have proven capable of forecasting space weather events with a much higher accuracy with respect to long-used traditional empirical and physics-based models. Even though very few operational models are currently empowered by machine learning, it appears to be unavoidable that the community will embrace in the near future such powerful techniques. Indeed, it is hard to imagine the future of space weather without machine learning. Presently, we are moving one step further from the initial ‘early-adopter’ stage, where proof-of-principles models were elaborated and tested, and more consideration is being given to the issues of reliability, uncertainty, and trustworthiness of machine learning models, finding the right balance between physics priors and data-driven discovery. In this talk the speaker presents the state-of-the-art of machine learning applications for space weather problems and discusses a few challenges and opportunities that this field presents to us.
Propagation parameters of electromagnetic waves such as amplitude, phase and polarization are impacted when traveling within the ionospheric plasma of the Earth. Related effects can be used on one hand to monitor and study the ionosphere by analysing the changes of measured propagation parameters. On the other hand, space weather impact on the ionosphere may cause unwanted distortions of signal detection in modern ground and space-based radio systems applied in telecommunication, positioning, navigation and remote sensing. After clarifying the main terms, the talk focuses on the discussion of space weather induced changes of the ionospheric plasma and associated impact on radio wave propagation used in diverse applications. Besides ionizing solar radiation and ionospheric plasma dynamics also solar radio bursts may seriously impact the functionality of radio systems via interference.
In the recent years, thanks to Solar System exploration, our knowledge on the interactions between a planetary body and its local space environment, where perturbations of solar or non-solar origin may occur, has been dramatically increased. Our understanding of the so called planetary space weather science is of paramount importance also for getting clues on similar –in their nature– phenomena that evolve in the circum-terrestrial environment, nevertheless, at different temporal and spatial scales. Moreover, determining the properties of radiation environments inside planetary magnetospheres is one of the key challenges of magnetospheric physics research. At the same time, it allows the design and manufacturing of satellites and payloads that are resistant to hazardous environments. In this talk, the speaker will discuss some examples of space weather science approaches, especially in the context of the Outer Solar System exploration. Moreover, the speaker will try to evidence the role of theoretical and/or data-driven modeling during preparation for upcoming exploration missions and discuss some future perspectives.
Satellites in low Earth orbit travel through the uppermost layer of the neutral atmosphere, where their movement is affected by variations in the density and wind. These variations affect the amount of fuel required by active satellites to fulfil their mission, as well as the duration that debris objects remain in space. The number of objects in low Earth orbit has been rapidly increasing. With it, concerns over the long-term sustainability of the use of this region of space have been on the rise as well. The trend in the number of objects is due to the ever increasing relevance of satellite missions to our society, combined with technological developments such as miniaturisation and the rise of mega-constellations. But also in-orbit breakups of rocket stages and satellites have been major contributors. In this talk, the speaker will provide an overview of the physics and technology related to this topic, as well as the ways in which international collaboration will be essential to provide solutions.
The aurora borealis (to the north, and australis to the south of the Earth) are the most spectacular phenomena of a chain that connects the planet’s upper atmosphere to the solar activity. In this lecture, the speaker addresses the questions they raise: What solar origin ? What interaction between the solar wind and the space environment ? How are they formed? What are they witnessing? Do they exist elsewhere than on Earth? What research is still being done on auroras?
Space weather has affected aviation in many ways; effects include short-wave radio disturbance, single-event effects leading to upsets in electronics, Satellite Navigation systems disturbance via scintillation, solar radio burst effects on secondary surveillance radar, increased radiation dose at flight altitudes. In November 2018, a long process involving experts from many countries of the world came to a conclusion when the ICAO Air Navigation Commission and the Council of ICAO, the International Civil Aviation Organization, approved and published provisions in ICAO Annex 3 and guidance material on Space Weather in ICAO Document 10100. The advisories intend to provide the most up to date information on space weather impacts on aviation. The introduction of space weather in the ICAO framework has been a great achievement. What is still outstanding is the development of procedures that are globally standardized on the application of the advisories, as well as the provision of adequate space weather knowledge to pilots, controllers and other aviation personnel. Recent events are used to illustrate this. The talk will be about space weather for aviation: what´s been achieved – and what needs more work.
