Related papers: Solar illumination control of ionospheric outflow …
Using observations from MAVEN's Neutral Gas and Ion Mass Spectrometer (NGIMS), we characterize the seasonal, solar zenith angle (SZA), and solar flux dependent variations of the O$^+$ peak and the O$^+$/O$_2^+$ ratio in the topside…
Development of the ion-proton pulsar model extends it to the limit of large unscreened polar-cap potentials, for example, as in the Vela pulsar, in which ion charges differ only by small increments from their complete screening values. It…
The Sun's polar magnetic fields are directly related to solar cycle variability. The strength of the polar fields at the start (minimum) of a cycle determine the subsequent amplitude of that cycle. In addition, the polar field reversals at…
Low-energy ions of ionospheric origin constitute a significant contributor to the magnetospheric plasma population. Measuring cold ions is difficult though. Observations have to be done at sufficiently high altitudes and typically in…
We present a detailed analysis of oxygen ion velocity distributions in the extended solar corona, based on observations made with the Ultraviolet Coronagraph Spectrometer (UVCS) on the SOHO spacecraft. Polar coronal holes at solar minimum…
As a large-scale motion on the Sun, the meridional flow plays an important role in determining magnetic structure and strength and solar cycle. However, the meridional flow near the solar poles is still unclear. The Hinode observations show…
Minimal observational evidence exists for fast transition region (TR) upflows in the presence of cool loops. Observations of such occurrences challenge notions of standard solar atmospheric heating models, as well as their description of…
This paper presents research on polar cap ionosphere space weather phenomena conducted during the European Cooperation in Science and Technology (COST) action ES0803 from 2008 to 2012. The main part of the work has been directed toward the…
It is shown that for moderately hot polar caps (with effective temperature of $\sim 10^6$ K), the efficiency of polar gap acceleration is lower compared to the case in which the polar caps are relatively cool and inverse Compton scattering…
This paper proposes that the ion temperature is several times the local electron temperature in the hot onset phase and at the above-the-loop region of solar flares. The paper considers: the evidence of spectral line Doppler widths…
We could infer a secular decreasing trend in the poloidal to toroidal solar magnetic flux amplification factor ( Af) using geomagnetic observations ( classic and IHV corrected aa indices) during the sunspot cycles 9-23. A similar decreasing…
Using SDO/HMI and SDO/AIA data for sunspot groups of the 24th solar cycle, we analyzed magnetic properties and He II 304 emission in leading and following sunspots separately. Simultaneous examination of umbral magnetic properties and…
We discuss and measure the phase shift imposed onto a radially polarized light beam when focusing it onto an $^{174}\text{Yb}^{+}$ ion. In the derivation of the expected phase shifts we include the properties of the involved atomic levels.…
In this paper, we analyze the high-resolution UV spectra for a C1.7 solar flare (SOL2017-09-09T06:51) observed by the \textit{Interface Region Imaging Spectrograph} (\textit{IRIS}). {We focus on the spectroscopic observations at the…
Measurements conducted with the ASPERA-4 instrument and the magnetometer of the Venus Express spacecraft show that the dynamic pressure of planetary O+ ion fluxes measured in the Venus wake can be significantly larger than the local…
The emission of the upper atmosphere of the Sun is closely related to magnetic field concentrations at the solar surface. It is well established that this relation between chromospheric emission and magnetic field is nonlinear. Here we…
During a solar flare, the fluxes in various lines and continua of the solar spectrum increase, leading to enhanced ionization of the illuminated part of the Earth's ionosphere and an increase in the total electron content (TEC). It has been…
We present the results of multi wavelength, co-spatial and near co-temporal observations of jets above a sunspot light bridge. The data were obtained with the Solar Optical Telescope (SOT) on board Hinode, the Interface Region Spectrograph…
Spin effects in the tunneling regime of strong field ionization of hydrogenlike highly charged ions in linearly as well as circularly polarized laser fields are investigated. The impact of the polarization of a laser field on the spin…
This paper concerns the theory of non-recollisional ionization or detachment of atoms or ions by intense few-cycle pulses. It is shown that in certain conditions of pulse duration, peak intensity and carrier-envelope phase, the ionization…