Related papers: Sun-Heliosphere Observation-based Ionization Rates…
We study the solar-activity and solar-polarity dependence of galactic cosmic-ray intensity (CRI) on the solar and heliospheric parameters playing a significant role in solar modulation. We utilize the data for cosmic-ray intensity as…
Chromospheric plages are distributed between mid-latitude and the Equator and never close to the Poles. Therefore, we suspect that the inclination angle of the solar rotation axis has an impact on the observable chromospheric emission. We…
Solar irradiance variability has been monitored almost exclusively from the Earth's perspective. {We present a method to combine the unprecedented observations of the photospheric magnetic field and continuum intensity from outside the…
The composition and structure of the upper atmospheres of Extrasolar Giant Planets (EGPs) are affected by the high-energy spectrum of their host stars from soft X-rays to EUV. This emission depends on the activity level of the star, which…
The solar wind (SW) is an outflow of the solar coronal plasma, expanding supersonically throughout the heliosphere. SW particles interact by charge exchange with interstellar neutral atoms and on one hand, they modify the distribution of…
We introduce an updated, time-dependent treatment to the split-tail ("croissant-like") heliosphere model with data-driven solar wind conditions at 1 au, to study the evolution of the heliosphere with solar-cycle variations in plasma speed,…
Properties of the Sun's interior can be determined accurately from helioseismological measurements of solar oscillations. These measurements, however, are in conflict with photospheric elemental abundances derived using 3-D hydrodynamic…
The regions in which stellar winds interact with the interstellar medium, also known as astrospheres, can be observed in detail through the thermal emission of the interstellar dust particles, resided in plasma. Interstellar dust is also…
A new collection of photodissociation and photoionisation cross sections for 102 atoms and molecules of astrochemical interest has been assembled, along with a brief review of the basic processes involved. These have been used to calculate…
The Solar and Heliospheric Observatory (SOHO) was launched in December 1995 with a suite of instruments designed to answer long-standing questions about the Sun's internal structure, its extensive outer atmosphere, and the solar wind. This…
Wave-particle instabilities driven by departures from local thermodynamic equilibrium have been conjectured to play a role in governing solar wind dynamics. We calculate the statistical variation of linear stability over a large subset of…
The heliosphere serves as a probe of interstellar material (ISM) close to the Sun. Measurements of ISM inside and outside of the heliosphere show that we reside in typical warm partially ionized ISM that can be successfully modeled using…
Gravitational lensing of invisible streaming matter towards the Sun could be the explanation of the puzzling solar flares and the unexplained solar emission in the EUV. Assuming that this invisible matter has some form of interaction with…
Absorption of the Lyman-$\alpha$ radiation on Interstellar Neutral Hydrogen (ISN H) atoms in the heliosphere is a potentially important effect to account for in precise gas distribution simulations. In this paper we develop a method to…
Helioseismic data for solar cycles 23 and 24 have shown unequivocally that solar dynamics changes with solar activity. Changes in solar structure have been more difficult to detect. Basu & Mandel (2004) had claimed that the then available…
We present observations of >10-100 keV/nucleon suprathermal (ST) H, He, O, and Fe ions associated with crossings of the heliospheric current sheet (HCS) at radial distances <0.1 au from the Sun. Our key findings are: 1) very few heavy ions…
Helioseismology has shown that the chemical composition of the Sun has changed over its lifetime. The surface abundance of helium and heavy elements is believed to have decreased by up to 10% relative to their initial values. However, this…
Some of the natural variability in climate is understood to come from changes in the Sun. A key route whereby the Sun may influence surface climate is initiated in the tropical stratosphere by the absorption of solar ultraviolet (UV)…
We present an empirical model for auroral (90--150 km) electron--ion pair production rates, ionization rates for short, derived from SSUSI (Special Sensor Ultraviolet Spectrographic Imager) electron energy and flux data. Using the Fang et…
The properties of the solar wind, as measured in situ throughout the heliosphere, depend both on the characteristics of its coronal source and on the intrinsic processes governing its interplanetary evolution. Recently, radial and Parker…