Letters of Intent received in 2019

LoI 2021-2091
Focus Group for the Whole Heliosphere & Planetary Interactions (WHPI): New Insights into Solar Minimum

Date: 23 August 2021 to 25 August 2021
Location: Busan, Korea, Rep of
Contact: Bernard Jackson (bvjackson@ucsd.edu)
Coordinating division: Division E Sun and Heliosphere
Other divisions: Division F Planetary Systems and Astrobiology
Co-Chairs of SOC: Bernard V. Jackson (University of California, San Diego)
Giuliana de Toma (University Corporation for Atmospheric Research)
Mario Mark Bisi (UKRI STFC RAL Space)
Chair of LOC: None (None)



• Modelling of the current solar minimum and its direct comparisons to multiple data sets
• What have we learned from Parker Solar Probe with respect to the WHPI campaign periods and solar minimum?
• What have we learned from BepiColombo and Solar Orbiter with respect to the WHPI campaign periods and solar minimum?
• What have we learned from coordinated ground-based radio observations with respect to the WHPI campaign periods and solar minimum?
• How does our modern minimum compare with those we have good data for since the start of the Space Age?
• Space Weather at the Earth during the WHPI campaign periods and the current solar minimum



We are in a unique period of observing and measuring our Sun and the heliosphere throughout the solar system with a fleet of deep space and planetary spacecraft and a plethora of ground-based instruments. Great breakthroughs in observing locations are being made already by the Parker Solar Probe, the closest ever spacecraft to the Sun. Additionally, BepiColombo analyses during its cruise phase and planet flybys on the way to Mercury will provide new space weather insights, as well as information from the soon-to-be-launched Solar Orbiter mission. These are backed up by a whole selection of ongoing and novel data sets from extant missions and ground-based systems across all observing wavelengths and multiple different types of plasma, particle, and magnetic-field measurements. We have already seen that profound progress is possible when community-wide cooperation and coordination is accomplished, for example through the remarkable feat of imaging a black hole for the first time by coordinating the power of eight major radio observatories on four continents and over 200 astronomers. Given all this, the time is right to try to bring a large coordination of such activities so we can maximise our learning and understanding of our Sun and the heliosphere it creates. Thus, a set of targeted campaigns are being undertaken as The Whole Heliosphere & Planetary Interaction (WHPI) initiative. WHPI is a direct follow-on (and expansion) activity of previous endeavours looking at prior solar-minimum periods (namely, the Whole Sun Month – WSM 1996 – and Whole Heliosphere Interval – WHI 2008 – time periods). The goal will be to observe the full breadth of Sun - Earth - planets and to comprehensively-map the solar-minimum heliosphere via state-of-the-art models. Many of the WHPI campaigns are focussed around the Parker Solar Probe perihelia as these are times where the greatest amount of data are available. There will be similar focussed periods between Parker Solar Probe, BepiColombo, and Solar Orbiter also. All interactions associated with Sun/solar wind originating during this time period will be within the scope of the campaign: Travel time of heliospheric structures through the solar system means that a significantly longer time-period than a solar rotation is effectively considered.

The Presidents of Divisions E and F support the LoI for the GA Focus Meeting: "Whole Heliosphere and Planetary Interactions"

Others who have expressed interest in being on the SOC and participated in this LOI preparation are: Heidi Korhonen (Copenhagen, Denmark), Dibyendu Nandi (IISER Kolkata, India), and Cristina Mandrini (Buenos Aires, Argentina)