  This white paper is a call for a concerted effort to support total solar
eclipse observations over the next decade, in particular for the 21 August 2017
eclipse which will traverse the US continent. With the recent advances in image
processing techniques and detector technology, the time is ripe to capitalize
on the unique diagnostic tools available in the visible and near infrared
wavelength range to explore the physics of the corona. The advantage of coronal
emission lines in this wavelength range, over their extreme ultraviolet
counterparts, is (1) the significant radiative component in their excitation
process (in addition to the collisional excitation), which allows for
observations out to a few solar radii, (2) the higher spectral selectivity
available for imaging, giving well-defined temperature responses for each
bandpass (one line as opposed to many), and (3) the capability of polarization
measurements in a number of spectral lines. Consequently, the evolution of the
thermodynamic and magnetic properties of the coronal plasma can be explored
starting from the solar surface out to a few solar radii, namely the most
important region of the corona where the expansion of the solar magnetic field
and the acceleration of the solar wind occur. Since the planning of eclipse
observations will not be possible without the invaluable NASA-published total
solar eclipse bulletins by Espenak and Andersen, a call is also made to ensure
continued support for these efforts.

Solar and Stellar Astrophysics