Copyright © National Academy of Sciences. All rights reserved.
Solar and Space Physics: A Science for a Technological Society
67
3
Addressing Societal Needs
Societal aspirations for a secure, prosperous, and technologically sophisticated future are increasingly influenced by Earth’s near-space environment. Central to the decadal survey’s strategy is the intent
to achieve scientific results that will be useful to society; this chapter briefly reviews societal needs for
improved knowledge of solar and space physics phenomena related to the effects of space weather. 1
IMPACTS OF EARTH’S NEAR-SPACE ENVIRONMENT
The Climate System
The Sun’s photon energy is the main source of heat for the entire Earth system. Slight variations in this
light with the Sun’s 11-year activity cycle (Figure 3.1), and possibly on longer timescales, continuously
affect Earth’s climate and atmosphere, at times temporarily masking the effects of changing concentrations
of greenhouse gases. Earth’s atmosphere protects us from biologically damaging shorter-wavelength solar
ultraviolet emissions. These emissions fluctuate by orders of magnitude more than variations in the total
brightness, altering the ozone layer significantly. Solar-induced photochemical and dynamical changes
in Earth’s middle atmosphere may affect the climate at lower altitudes and in the upper atmosphere and
ionosphere through dynamical coupling of changing wave structures.
Precipitating electrons from the aurora affect the atmospheric chemistry in the polar regions. During
major magnetic storms, significant enhancements of nitric oxide concentrations occur in the auroral zone
and can literally propagate downward from space into the stratosphere. Nitric oxide plays an important
role in the chemistry of stratospheric ozone. The downward transport of auroral products is difficult to trace
and varies with the general circulation of the polar atmosphere, but it is clear that major space storms can
potentially modify stratospheric composition and reduce ozone densities for a period of time following
their occurrence.
1 See also Box 1.1, “Severe Space Weather Events—Understanding Societal and Economic Impacts.”
Solar and Space Physics: A Science for a Technological Society
67
3
Addressing Societal Needs
Societal aspirations for a secure, prosperous, and technologically sophisticated future are increasingly influenced by Earth’s near-space environment. Central to the decadal survey’s strategy is the intent
to achieve scientific results that will be useful to society; this chapter briefly reviews societal needs for
improved knowledge of solar and space physics phenomena related to the effects of space weather. 1
IMPACTS OF EARTH’S NEAR-SPACE ENVIRONMENT
The Climate System
The Sun’s photon energy is the main source of heat for the entire Earth system. Slight variations in this
light with the Sun’s 11-year activity cycle (Figure 3.1), and possibly on longer timescales, continuously
affect Earth’s climate and atmosphere, at times temporarily masking the effects of changing concentrations
of greenhouse gases. Earth’s atmosphere protects us from biologically damaging shorter-wavelength solar
ultraviolet emissions. These emissions fluctuate by orders of magnitude more than variations in the total
brightness, altering the ozone layer significantly. Solar-induced photochemical and dynamical changes
in Earth’s middle atmosphere may affect the climate at lower altitudes and in the upper atmosphere and
ionosphere through dynamical coupling of changing wave structures.
Precipitating electrons from the aurora affect the atmospheric chemistry in the polar regions. During
major magnetic storms, significant enhancements of nitric oxide concentrations occur in the auroral zone
and can literally propagate downward from space into the stratosphere. Nitric oxide plays an important
role in the chemistry of stratospheric ozone. The downward transport of auroral products is difficult to trace
and varies with the general circulation of the polar atmosphere, but it is clear that major space storms can
potentially modify stratospheric composition and reduce ozone densities for a period of time following
their occurrence.
1 See also Box 1.1, “Severe Space Weather Events—Understanding Societal and Economic Impacts.”