Societal and Science Case For Inner Heliospheric Solar Wind Constellation
Abstract
The solar wind exhibits large-scale and mesoscale structures whose presence and evolution directly affect Earth's space environment and can impact key assets on and orbiting Earth. Phenomena such as coronal mass ejections, co-rotating interaction regions, and interplanetary shocks can have rapid and dramatic geospace effects via large-scale fluctuations in the interplanetary magnetic field, plasma pressure and density, and solar energetic particle (SEP) energization and propagation. Satellite constellations at the Earth-Sun Lagrange 1 (L1) point can only provide solar wind plasma and magnetic field measurements ~ 1 hr in advance of their arrival at Earth, limiting our ability to forecast significant events and avoid technological and societal disaster; the recent loss of 40 Starlink satellites due to geomagnetic storm activity, for example, highlights the need for 1-2 day advanced space weather forecasts. To prepare our technological society for the next decade and beyond, we need to have a network of upstream spacecraft at various radial distances from Sun whose data could be assimilated near real-time into space weather modeling. This could be achieved by placing constellations at the Mercury, Venus and Earth Lagrange points, which - with international collaboration is possible over - the coming decades. As a first step, we propose the first of its kind Pathfinder mission, placing spacecraft into Venus-Sun Lagrange points to enable study of the physical processes responsible for the large- to meso-scale plasma and magnetic structures in the inner heliosphere and energetic particle dynamics. This mission will provide the first in-situ, synchronized, multi-point magnetic field and energetic particle measurements in a region only sparsely covered by single-point measurements from flybys of sun- and Mercury-bound missions since the end of Venus Express in 2014. When one or more of the Venus-Sun Lagrange points lies sunward from the Earth and/or further towards the west limb of the Sun, a coverage period of ~50 Days/Earth year, these observations would allow us to develop and test space weather warning algorithms based on coronagraphs and in-situ observations of the solar wind at L1; even when not in the flight path of Earthward-bound solar wind, the multiscale nature of the observations would provide key insight into the propagation and evolution of solar wind structures.
- Publication:
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44th COSPAR Scientific Assembly. Held 16-24 July
- Pub Date:
- July 2022
- Bibcode:
- 2022cosp...44.1607N