Geospace Missions for Space W eather and the Next S cientific C hallenges

1. Geospace Missions for Space Weather and the Next Scientific Challenges James Spann, United States, NASA February 11, 2014

2. Beautiful motivation

3. Geospace Missions • Observation Requirements • Space-Based • Ground-Based • Future science missions • Next Major Science Challenges • Flare prediction – solar surface and subsurface dynamics • Geoeffectiveness of Space Storms – interplanetary magnetic field • Ionospheric variability – ubiquitous impact • Discipline Challenge • Operation tools and workforce

4. Observation Requirements

5. Space Weather Observing Systems for Geospace * science missions ** science missions in development

6. Ground-Based Ionospheric Sensors

7. INTERMAGNET Sites

8. Top rated future science missions in the US highlight Geospace space weather relevant missions • The first new STP science target is to understand the outer heliosphere and its interaction with the interstellar medium, as illustrated by the reference mission Interstellar Mapping and Acceleration Probe (IMAP). Implementing IMAP as the first of the STP investigations will ensure coordination with NASA Voyager missions. The mission implementation also requires measurements of the critical solar wind inputs to the terrestrial system. • The second STP science target is to provide a comprehensive understanding of the variability in space weather driven by lower-atmosphere weather on Earth. This target is illustrated by the reference mission Dynamical Neutral Atmosphere-Ionosphere Coupling (DYNAMIC).

9. Top rated future science missions in the US highlight Geospace space weather relevant missions • The third STP science target is to determine how the magnetosphere-ionosphere-thermosphere system is coupled and how it responds to solar and magnetospheric forcing. This target is illustrated by the reference mission Magnetosphere Energetics, Dynamics, and Ionospheric Coupling Investigation (MEDICI). • The survey committee describes the next science target best addressed by the LWS program (is) a mission to understand how Earth’s atmosphere absorbs solar wind energy, illustrated by the Geospace Dynamics Constellation (GDC).

10. IMAP • A notional spacecraft and instrument implementation for IMAP is based largely on ACE and IBEX. IMAP is a Sun-pointed spinner, with spin axis readjustment every few days to provide all-sky maps every 6 months. Mission goals are achieved with a 2-year baseline, including transit to L1, with possible extension to longer operation (which would be particularly beneficial for long-term L1 monitoring). • Observations from many spacecraft () contribute dramatically to understanding solar energetic particle events, the importance of suprathermal ions for efficient further energization, the sources and evolution of solar wind, solar-wind and energetic-particle inputs into geospace, and evolution of the solar-heliospheric magnetic field. These observables are controlled by a myriad of complex and poorly understood physical effects acting on distinct particle populations. IMAP combines highly sensitive PUI (pick-up ions) and suprathermal-ion sensors to provide the critical species, spectral coverage, and temporal resolution to address these physical processes. As an L1 monitor, IMAP also would fill a critical hole in Sun-Earth system observations by measuring the solar wind

11. New discoveries at the interface of the the heliosphere and the local intergallactic space give us some insight on very deep space weather. IMAP would explore that interface further and provide a robust platform for a L1 monitor of space weather.

12. DYNAMIC • By resolving the fundamental question of meteorological influences from below, DYNAMIC will firmly connect the ionosphere-thermosphere (IT) system to Earth’s lower atmosphere, capturing a critical, missing component of scientific understanding of geospace and providing a critical new capability () at an important boundary in near-Earth space. In establishing the relative importance of thermal expansion, upwelling, and advection in defining total mass density changes, DYNAMIC will also provide information fundamental to understanding the global IT response to forcing from above. This investigation of the contribution of the lower atmosphere to the mean structure and dynamics of the IT system reflects a scientific appreciation of the importance of these drivers gained since the 2003 solar and space physics decadal survey.

13. DYNAMIC targets the effects of lower atmospheric processes on conditions in space, characterizing how the energy and momentum carried into this region by atmospheric waves and tides interact and compete with solar and magnetospheric drivers. Full spatial and temporal resolution of the wave inputs is accomplished by using two identical, high-inclination, space-based platforms in similar orbits, offset by 6 hours of local time

14. MEDICI • MEDICI will both benefit from and enhance the science return from almost any geospace mission that flies contemporaneously, such as upstream solar wind monitors, geostationary satellites, and low-Earth-orbit missions. In particular, by providing global context and quantitative estimates for magnetospheric- ionospheric plasma and energy exchange, MEDICI has significant value for missions investigating ionospheric conditions, outflow of ionospheric plasma into the magnetosphere, energy input from the magnetosphere into the ionosphere, and aurora ionosphere-thermosphere coupling in general. Thus it will add value to a host of possible ionospheric strategic missions, Explorers, and rocket and balloon campaigns. Further, with continuous imaging and in situ observations from two separate platforms, it would provide indispensable validating observations of system-level interactions and processes that feed geospace predictive models. The likely long duration of the notional MEDICI mission will allow it to provide a transformative framework into which additional future science missions can naturally fit.

15. MEDICI targets complex, coupled, and interconnected multiscale behavior of the magnetosphere-ionosphere-thermosphere system by providing high-resolution, global, continuous three-dimensional images of the ring current(orange), plasmasphere (green), aurora, and ionospheric-thermospheric dynamics and flows, as well as multipoint in situ measurements.

16. Geospace Dynamic Constellation • GDC will make measurements critical to understanding how the IT system regulates the response of geospace to external forcing. The constellation of satellites will provide a complete picture of the dynamic exchange of energy and momentum that occurs between ionized and neutral gases at high latitudes, providing the HSO a critical capability for measuring the response and electrodynamic feedback of Earth’s IT system to drivers originating in the solar wind and magnetosphere. GDC will also determine the global response of the IT system to magnetic activity and storms and expose how changes in the system at different locations are related. Finally, it will determine the influence of forcing from below on the IT system, by measuring the global variability of thermospheric waves and tides on a day-to-day basis with the spatial resolution that only a constellation of satellites can provide.

17. Features of the 6-spacecraft GDC mission concept

18. Are these Missions Real? • The recommended highest priority science has significant space weather relevance in Geospace • The science focus is real

19. Challenges • Next Major Science Challenges • Flare prediction – solar surface and subsurface dynamics • Geoeffectiveness of Space Storms – interplanetary magnetic field • Ionospheric variability – ubiquitous impact • Discipline Challenge • Operation tools and workforce development

20. Scientific Challenge:Geoeffectiveness • Significant progress has been made predicting arrival time of space storms • How geoeffective will a storm be? • Sometimes yes, sometimes no • Orientation of magnetic field and velocity are the first order determinants • We have magnetic field orientation and magnitude at L1 with in situ monitors • Goal: measure the orientation of the magnetic field as it evolves on its way to Earth

21. A concept to measure the inner solar system magnetic field • Zodiacal light is scattered sunlight off interplanetary dust grains • Dust grains rotate when illuminated, and become charged when exposed to UV and charged particles • A rotating charged grain will align itself with mag field • Alignment of a cloud of dust grains will produce polarized scattered light when illuminated • Using polarimetry measurements and knowledge of dust grain optical extinction coefficient, the mag field direction can be inferred

22. Scientific Challenge:Ionospheric Variability • Ionospheric variability is arguably the most ubiquitous of all space weather effects on society • Understanding the nature of the variability is very difficult • Remote observations of the variability is elusive, but possible on large and small scales • To make progress, in situ, ground-based, and large scale observations are needed

23. Day to day variability can be outstanding and currently defies prediction Noon Sector, December 24, 25, 26, 2011 • Daytime TEC : LISN Network – P.I. C. Valladares • Outstanding day-to-day variability in equatorial ionosphere while! New techniques show us behavior of the ionosphere that is completely unexpected. From Thomas Immel’s presentation at AMS Space Weather Conference 2.4-2014

24. Discipline Challenge: • Develop a community of space weather operators • Space science - scientists • Space weather - meteorologists • Develop an effective process to create decision making tools for space weather • Governments • Industries • Meteorology paradigm • Users/developers/scientists work very closely in an iterative fashion