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5. Identify key long-term solar and heliospheric data sets and recommend approaches to ensure that
they are continued and archived (§10.5.5.5).
6. Continue support of laboratory plasma physics at current or higher levels to complement spacecraft
measurements in understanding basic heliophysical processes (§10.5.5.6).
7. NASA, the National Oceanic and Atmospheric Administration (NOAA), and the Department of
Defense are encouraged to develop a plan for a mission at the L5 Lagrangian point to conduct high-priority
helioseismology studies and develop advanced capabilities to forecast space weather (§10.5.5.7).
10.3 SIGNIFICANT ACCOMPLISHMENTS DURING THE PREVIOUS DECADE
There has been considerable progress along with many surprising discoveries in the disciplines that
constitute solar and heliospheric physics since publication in 2003 of the National Research Council
(NRC) decadal survey, The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and
Space Physics. 1 In the following four subsections, organized by the four SHP science goals outlined in
Section 10.1, the panel describes a small sampling of recent developments. Accomplishments or goals that
address the three decadal survey guiding motivations (M1-M3) are also noted. 2
10.3.1 Determining How the Sun Generates the Quasi-cyclical Variable
Magnetic Field That Extends Throughout the Heliosphere
As emphasized in the 2003 decadal survey, 3 an enduring major science goal is to determine how
the Sun generates its quasi-cyclical variable magnetic field. The practical goal of such research is to learn
enough to be able to help to predict the changing space environment and its societal impact (motivation
M2). Here the SHP panel sketches four of the many notable accomplishments of the past decade toward
meeting these goals.
With a wide array of ground- and space-based sensors, solar activity in its many forms was observed to
fall in 2008-2009 to low levels not seen for nearly a century. Solar activity is driven by the solar magnetic
field, and the recent decline in the polar magnetic field flux is shown in Figure 10.2. The sharp decline
was not generally expected. However, researchers noted that before the activity minimum measurements
by ground-based instruments and space-based instruments on the Solar and Heliospheric Observatory
(SOHO) showed unusually small amounts of magnetic flux near the poles of the Sun. Considered by some
to be a useful precursor of the strength of an activity cycle, the low flux levels led to predictions that the
current solar cycle maximum would be the lowest since polar flux measurements became available—as
appears to be the case. Other venerable solar activity precursors that suggested a high level of activity
proved to be spectacularly unreliable. Vital observational work in this research is continuing with groundbased and space-based assets, particularly because there is a chance that the Sun is entering a sustained
period of low activity.
The effects of record low solar activity were observed throughout the heliosphere. Among the prominent
effects with societal consequences were these: cosmic ray fluxes near Earth reached the highest levels on
record, and reduced heating of Earth’s upper atmosphere by solar UV radiation led to less drag on satellites.
1 National Research Council (NRC), The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and Space Physics,
The National Academies Press, Washington, D.C., 2003; and NRC, The Sun to the Earth—and Beyond: Panel Reports, The National
Academies Press, Washington, D.C., 2003.
2 The motivations referred to in this section are those outlined in the introduction to Part II of this report: M1, Understand our
home in the solar system; M2, Predict the changing space environment and its societal impact; M3, Explore space to reveal universal
physical processes.
3 NRC, The Sun to the Earth—and Beyond: Panel Reports, 2003, p. 12.
Solar and Space Physics: A Science for a Technological Society
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SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
5. Identify key long-term solar and heliospheric data sets and recommend approaches to ensure that
they are continued and archived (§10.5.5.5).
6. Continue support of laboratory plasma physics at current or higher levels to complement spacecraft
measurements in understanding basic heliophysical processes (§10.5.5.6).
7. NASA, the National Oceanic and Atmospheric Administration (NOAA), and the Department of
Defense are encouraged to develop a plan for a mission at the L5 Lagrangian point to conduct high-priority
helioseismology studies and develop advanced capabilities to forecast space weather (§10.5.5.7).
10.3 SIGNIFICANT ACCOMPLISHMENTS DURING THE PREVIOUS DECADE
There has been considerable progress along with many surprising discoveries in the disciplines that
constitute solar and heliospheric physics since publication in 2003 of the National Research Council
(NRC) decadal survey, The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and
Space Physics. 1 In the following four subsections, organized by the four SHP science goals outlined in
Section 10.1, the panel describes a small sampling of recent developments. Accomplishments or goals that
address the three decadal survey guiding motivations (M1-M3) are also noted. 2
10.3.1 Determining How the Sun Generates the Quasi-cyclical Variable
Magnetic Field That Extends Throughout the Heliosphere
As emphasized in the 2003 decadal survey, 3 an enduring major science goal is to determine how
the Sun generates its quasi-cyclical variable magnetic field. The practical goal of such research is to learn
enough to be able to help to predict the changing space environment and its societal impact (motivation
M2). Here the SHP panel sketches four of the many notable accomplishments of the past decade toward
meeting these goals.
With a wide array of ground- and space-based sensors, solar activity in its many forms was observed to
fall in 2008-2009 to low levels not seen for nearly a century. Solar activity is driven by the solar magnetic
field, and the recent decline in the polar magnetic field flux is shown in Figure 10.2. The sharp decline
was not generally expected. However, researchers noted that before the activity minimum measurements
by ground-based instruments and space-based instruments on the Solar and Heliospheric Observatory
(SOHO) showed unusually small amounts of magnetic flux near the poles of the Sun. Considered by some
to be a useful precursor of the strength of an activity cycle, the low flux levels led to predictions that the
current solar cycle maximum would be the lowest since polar flux measurements became available—as
appears to be the case. Other venerable solar activity precursors that suggested a high level of activity
proved to be spectacularly unreliable. Vital observational work in this research is continuing with groundbased and space-based assets, particularly because there is a chance that the Sun is entering a sustained
period of low activity.
The effects of record low solar activity were observed throughout the heliosphere. Among the prominent
effects with societal consequences were these: cosmic ray fluxes near Earth reached the highest levels on
record, and reduced heating of Earth’s upper atmosphere by solar UV radiation led to less drag on satellites.
1 National Research Council (NRC), The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and Space Physics,
The National Academies Press, Washington, D.C., 2003; and NRC, The Sun to the Earth—and Beyond: Panel Reports, The National
Academies Press, Washington, D.C., 2003.
2 The motivations referred to in this section are those outlined in the introduction to Part II of this report: M1, Understand our
home in the solar system; M2, Predict the changing space environment and its societal impact; M3, Explore space to reveal universal
physical processes.
3 NRC, The Sun to the Earth—and Beyond: Panel Reports, 2003, p. 12.