Geocoronal hydrogen observations spanning three solar minima

Doppler Profile Measurements of the Geocoronal Hydrogen Balmer Alpha Line

Results of high-resolution measurements of the geocoronal hydrogen Balmer alpha line profile made during se4eral nights in December 1971, May 1972, and October 1972 are presented. The measured intensities are found to be in general agreement with the theory and earlier measurements under essentially similar conditions, and the measured geocoronal hydrogen temperatures are found to be somewhat l...

Deciphering solar magnetic activity: on grand minima in solar activity

The Sun provides the energy necessary to sustain our existence. While the Sun provides for us, it is also capable of taking away. The weather and climatic scales of solar evolution and the Sun-Earth connection are not wellunderstood. There has been tremendous progress in the century since the discovery of solar magnetism—magnetism that ultimately drives the electromagnetic, particulate, and eru...

Seismology of solar spicules based on Hinode/SOT observations

Three Factors Influencing Minima in SGD

We study the properties of the endpoint of stochastic gradient descent (SGD). By approximating SGD as a stochastic differential equation (SDE) we consider the Boltzmann-Gibbs equilibrium distribution of that SDE under the assumption of isotropic variance in loss gradients. Through this analysis, we find that three factors – learning rate, batch size and the variance of the loss gradients – cont...

Thermochemical solar hydrogen generation.

Solar direct, indirect and hybrid thermochemical processes are presented for the generation of hydrogen and compared to alternate solar hydrogen processes. A hybrid solar thermal/electrochemical process combines efficient photovoltaics and concentrated excess sub-bandgap heat into highly efficient elevated temperature solar electrolysis of water and generation of H2 fuel utilizing the thermodyn...