We propose to deploy two unique ground-based experiments with the goal of furthering our understanding of coronal magnetism and thermal structure, and to test novel instrumentation during the 21…

This is a $99,793.19 grant awarded by the National Aeronautics and Space Administration (NASA) to the University Corporation for Atmospheric Research (UCAR), a non-profit consortium of over 115 universities that manages the National Center for Atmospheric Research (NCAR). The grant will fund two unique ground-based experiments during the total solar eclipse on August 21, 2017 to further the understanding of coronal magnetism and thermal structure, and to test novel instrumentation. The first experiment will use a narrow-band infrared imager to capture intensities and context images of magnetically sensitive coronal emission lines. The second experiment will provide instantaneous measurements of the Stokes parameters of selected coronal lines using an innovative commercial sensor coupled with polarizers and a liquid crystal modulating retarder. The data will be analyzed using existing methods and will complement observations from other eclipse experiments and spacecraft. This work is relevant to NASA's 2017 eclipse opportunity and will enhance understanding of solar space weather and test new camera technology. The grant does not have a set-aside designation.

We propose to deploy two unique ground-based experiments with the goal of furthering our understanding of coronal magnetism and thermal structure, and to test novel instrumentation during the 21 august 2017 total solar eclipse. First, a narrow-band imager at infrared wavelengths will provide both intensities and context images of the magnetically sensitive coronal emission lines of FE IX 2855 NM, MG VIII 3028 NM and SI IX 3935 NM. We will take advantage of new, inexpensive commercial filters which match well the bandpasses needed for coronal emission line work. Knowledge of the spatial brightness distribution of these lines is needed for identifying the optimal lines for coronal magnetometry. The second novel experiment will provide instantaneous measurements of the stokes parameters of two selected coronal lines from visible to near infrared wavelengths, at high frame rates. An innovative commercial sensor, which is coupled with an array of linear polarizers oriented at four different angles, will be augmented with a liquid crystal modulating retarder element to produce polarization measurements of coronal light. The new technology is simple and compact enough for potential deployment on future spacecraft, perhaps even cubesats, with applications for heliophysics and the astrophysics communities. These data will be analyzed using: existing stokes inversion methods at the high altitude observatory (HAO); the haos-diper atomic data and spectra tool developed by judge; and forward codes in IDL solarsoft (gibson 2015) to diagnose coronal magnetic fields and plasma structures. The data will also be used in conjunction with observations from EUV experiments on NASA s hinode and SDO spacecrafts and with mauna LOA ground-based coronal observations from comp and cosmo k-COR coronagraphs. Additionally, these data will complement and be used to augment eclipse data from experiments between three ncar laboratories and the harvard-smithsonian center for astrophysics (ncar FTS and air-spec). We anticipate that data from this field campaign will allow US to define the magnetic and thermal structure of the corona far more precisely than done through earlier eclipses, and greatly enhance the value of other data and modeling efforts planned for this unusual natural opportunity. This work is relevant to the NASA 2017 eclipse opportunity. IT will provide rare observations of IR emission lines from the ground of a quality that can only be obtained during an eclipse to help identify optimal observations for coronal magnetometry and further our understanding of coronal magnetic and thermal structure. This work will enhance our understanding of how the sun generates space weather and test new camera technology for solar and stellar polarimetry. This new information can benefit the upcoming solar probe plus mission. Our work will include significant public outreach and training of at least one university student.