Solar Influences on Global Change (1994) / Chapter Skim
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1 INTRODUCTION
1 INTRODUCTION
Pages 13-22
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From page 13... ...
Without solar radiation, photosynthesis would cease. Solar radiation and high energy particles impinge continually on the envelope of gases and plasma that surrounds and protects the narrow habitable layer of the Earth's surface.
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From page 14... ...
radiation and the solar wind and energetic particles from the Sun undergo large changes related to the presence of active regions in the solar atmosphere. These changes cause dramatic variability in the Earth's upper atmosphere, ionosphere, and magnetosphere.
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The solar cycle variation in the spectrally integrated, or total, solar irradiance is indicated by the dot-dash line.
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Solar radiation at wavelengths from about 150 to 310 nm is absorbed primarily in the middle atmosphere, which is conventionally defined as being that atmospheric region from about 15 to 100 km, between the troposphere and the thermosphere. Deposition of the Sun's energetic particle input to the global Earth system is more complicated.
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From page 17... ...
in the zonal wind in the tropical lower stratosphere. The main problem in quantitatively explaining statistical associations between solar variability parameters and sizable climate and weather effects is that the amount of energy in variable solar energy inputs is small compared both to the incoming solar energy itself and to lower atmosphere energetics.
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From page 18... ...
18 _ CO _ <: tr UJ ~ > Z o Z o ~: 111 z - o o~ Co~ o o o Co~ O .
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From page 19... ...
Solar UV radiation from 200 to 300 rim is believed to vary by a few percent, which implies that the energy associated with changes in this radiation is a factor of 10 or so less than that associated with total irradiance variations. Energetic particle sources possess still less energy.
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From page 20... ...
Energy from the Sun, whether as photons, energetic particles, or from solar wind-magnetosphere interactions, and whether deposited at low or high latitudes, is eventually distributed over the entire globe by the continuous motions of the Earth's atmosphere and oceans. Because of this, chemical, radiative, and dynamical perturbations generated by solar variability may be transported to different latitudes and altitudes; this absence of specific spatial and altitude boundaries within the global Earth system means that direct solar forcing of atmospheric regions remote from the biosphere may nevertheless affect it indirectly to some extent.
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From page 21... ...
In this case, quantitative physical laws are formulated and their predictive capability is verified with retrospective data as well as by predictions into the future. The goal of research in solar influences on global change then is the clevelopment of the necessary data bases and understanding of the physical processes that lead to the ability to assess and predict the behavior of the Sun and its influence on the Earth system.
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From page 22... ...
The Working Group on Solar Influences on Global Change met twice, in November 1990 and March 1991. Since then the topic has been the focus of three meetings: a Workshop on Solar-Terrestrial Impacts of Global Change, sponsored by the High Altitude Observatory in Boulder, CO, in May 1991; an international symposium on The Sun as a Variable Star: Solar and Stellar Irradiance Variations, International Astronomical Union, Colloquium No.
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