Exploring the solar poles: the last great frontier of the sun

Observations of the Sun’s poles is fundamental to understanding and predicting the solar cycle, constraining polar kilo-Gauss flux patches and plasma jets and illuminating the origin of the fast solar wind. This white paper argues the case for novel out-of-ecliptic observations of the Sun’s polar region in conjunction with existing or future multi-vantage point heliospheric observatories

Causality in heliophysics: Magnetic fields as a bridge between the Sun’s interior and the Earth’s space environment

Our host star, the Sun, is a middle-aged main sequence G type star whose activity varies. These variations are primarily governed by solar magnetic fields which are produced in the Sun’s interior via a magnetohydrodynamic dynamo mechanism. Solar activity manifests across different timescales, spanning transient phenomena such as flares, energetic particle events and coronal mass ejections to short to long-term modulation of solar irradiance, plasma winds, open flux and cosmic ray flux in the heliosphere. Collectively, these phenomena define space weather and space climate, which impact the state of the near-Earth space environment, the Earth’s magnetosphere, atmosphere and our space-reliant technologies. Understanding physical processes that are at the heart of solar variability and which causally connect the Sun–Earth system is therefore of immense importance to humanity. Such understanding leads to predictions of the impact of solar activity on our planet and provides a window to explore the plasma universe and other star–planet systems, including assessing the habitability of (exo)planets. In this review, based on our research on the solar–terrestrial system and extant scientific literature, we illuminate processes related to the genesis of solar magnetic fields in the Sun’s interior, their emergence and evolution, their manifestation as solar eruptive events, and their eventual impact on the geospace environment mediated via solar winds and storms. We focus on few phenomena that establish causal connections and demonstrate how our current understanding can lead to development of predictive capabilities encompassing the domain of heliophysics

Long-term solar variability: ISWAT S1 cluster review for COSPAR space weather roadmap

The Committee on Space Research (COSPAR) is updating its Roadmap on Space Weather. As input for this update, the COSPAR International Space Weather Action Teams (ISWAT) were asked to provide an overview of the current state-of-the-art and advancements since the last Roadmap (Schrijver et al., 2015), identifying gaps and opportunities for moving forward within the next 5 years — based on ongoing and planned missions, available modeling, and observational capabilities — and presenting an outlook beyond 5 years and recommendations on reaching long-term goals. While space weather is typically associated with short-term solar activity, knowledge of past solar variability observed and recorded through various parameters, including historical space weather events, informs us about the range of possible solar fluctuations. This long-term solar variability, belonging to the domain of space climate, is the prime focus of the ISWAT S1 Cluster. The goal of this paper is to describe the key objectives of the three S1 Action Teams, summarize the current state of knowledge of the topic that each team is focusing on, and identify the key science gaps that need to be addressed in each area