NCAR

Suppression of the polar tongue of ionization during the 21 August 2017 solar eclipse

Polar maps of differential TEC
Saturday, August 4, 2018

It has long been recognized that during solar eclipses, the ionosphere-thermosphere system changes greatly within the eclipse shadow, due to the rapid reduction of solar irradiation.

Long-lasting response of the global thermosphere and ionosphere to the 21 August 2017 solar eclipse

Long-lasting response of the global thermosphere and ionosphere
Sunday, August 5, 2018

Explains Wenbin Wang and others, previous studies have been devoted to examining the ionosphere and thermosphere response during the solar eclipse, but the post-eclipse response of the global ionosphere and thermosphere has not previously been well quantified.

MHD simulation of prominence eruption

A 3D MHD simulation of the eruption of a prominence-carrying coronal flux rope
Monday, August 6, 2018

Yuhong Fan and others carry out magnetohydrodynamic (MHD) simulations of the quasi-static evolution and eruption of a twisted coronal flux rope under a coronal streamer built up by an imposed flux emergence at the lower boundary.

Global responses of the coupled thermosphere and ionosphere system to the August 2017 great American solar eclipse

Global maps
Wednesday, August 1, 2018

It is commonly believed that solar eclipses have a great impact on the ionosphere-thermosphere (I-T) system within the eclipse shadow, but little attention has been paid to the global responses to them.

Experimental testing of scattering polarization models

Broadband fractional polarization Q/I, U/I, and V/I
Wednesday, August 1, 2018

We realized a laboratory experiment to study the polarization of the Na I doublet at 589:3 nm, in the presence of a magnetic eld. The purpose of the experiment is to test the theory of scattering polarization for illumination conditions typical of astrophysical plasmas.

Measured performance of shadow-cast coated gratings for spectro-polarimetric applications

Measured vector efficiency of an echelle grating
Wednesday, August 1, 2018

Roberto Casini et al report on the measurements of the vector efficiency of a reflective blazed diffraction grating, which was specially coated in order to reduce the level of polarization in the diffracted light.

Solar physics from unconventional viewpoints

An overview of interesting vantage points, highlighting previous extra-Sun-Earth-line (extra-SEL) missions
Thursday, July 26, 2018

We explore new opportunities for solar physics that could be realized by future missions providing sustained observations from vantage points away from the Sun-Earth line.

On the weak field approximation of Ca II 8542 A

Kawakami diagrams for the linear polarization of the Ca II 8542 A line
Thursday, July 26, 2018

The weak field approximation is a conceptually simple and computationally light method for inferring the magnetic field strength and its orientation in the Sun’s atmosphere.

Evolution of the Global Solar Magnetic Field over 4 Solar Cycles: Use of the McIntosh Archive

Butterfly-type plots of all of the McA data
Thursday, July 26, 2018

The McIntosh Archive consists of a set of hand-drawn solar Carrington maps created by Patrick McIntosh from 1964 to 2009. McIntosh used mainly H, He-I 10830Å and photospheric magnetic measurements from both ground-based and NASA satellite observations.

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