WHPI session at AGU

Tracing solar activity through the heliosphere: Lessons learned from comparative solar minima. Abstracts due July 29th, 2020.

WHPI Web Colloquia

Next colloquium on Thursday, August 20th

WHPI Show and Tell Days

Monday-Tuesday September 14th-15th, 2020.

WHPI First Workshop

ON HOLD -- More information

What Is WHPI?

Whole Heliosphere and Planetary Interactions (WHPI) is an international initiative focused around the solar minimum period that aims to understand the interconnected sun-heliospheric-planetary system. The simpler magnetic configuration and infrequency of Coronal Mass Ejections (CMEs) makes solar minimum an ideal time to follow how the solar magnetic and radiative output propagates through the heliosphere and affects the Earth and planets' atmospheres and magnetospheres. The role of WHPI is to facilitate and encourage interdisciplinary activities through a series of coordinated observing campaigns and dedicated workshops where observers and modelers get together to discuss, compare, and combine research results.

A Little History

The international Whole Sun Month (WSM; 1996, special journal issue) and Whole Heliosphere Interval (WHI; 2008, special journal issue) were coordinated observing and modeling efforts to characterize the three-dimensional, interconnected solar-heliospheric systems during solar minimum. By focusing on particular solar rotations near solar minimum, specific structures and activity could be traced throughout the heliosphere and down into the Earth's space environment and upper atmosphere.

The Way Forward

We are approaching the end of solar cycle 24 (solar cycle progression), and have an unprecedented range of ground-based and space-based instruments deployed, including the exciting new Parker Solar Probe (PSP). The time is ripe for a third focus period: the Whole Heliosphere and Planetary Interactions (WHPI). The intervals have extended their discipline range with each iteration: from Sun-solar wind (WSM) to Sun-solar-wind-geospace (WHI). It is thus appropriate that WHPI will broaden the emphasis further to include planetary magnetospheres and atmospheres, and in particular, planetary space weather.

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. In combination with the two previous solar minimum campaigns (WSM and WHI), WHPI will enable scientists to carry out comparative studies of solar minima and to search for long-term trends.

WHPI spans the entire solar minimum period (approximately end of 2018 to beginning of 2020). For the purpose of coordinating targeted observations, we have identified a few focus “campaign” time periods that take advantage of solar-heliosphere-planetary synergies including, for example, PSP perihelia and the solar Carrington Rotation 2219 (June 29 - July 26, 2019) which includes the solar eclipse (July 2, 2019) that was observed and modeled by many. To help stimulate collaborative activities, we also note other time intervals with interesting synergies with other solar and planetary missions such as CR 2225 (December 10, 2019 - January 6, 2020), during the PSP Venus flyby. However, we emphasize that WHPI science is not limited to these time periods.

We will organize one or more workshops where observers and modelers can meet, and compare and combine research results. If there is strong interest, we will enable virtual participation. We will then coordinate the dissemination of this research through community meeting special sessions and a journal (TBD) topical issue.


All interested parties are encouraged to sign up for the WHPI mailing list, and visit this WHPI web page for further information.

Join us in creating a "third data point", as we chart our star's influence across the millennia!