Related papers: Peculiar Current Solar-Minimum - Structure of the …
This paper presents the analysis of 3D evolution of solar wind density turbulence and speed at various levels of solar activity between solar cycles 22 and 24. The solar wind data has been obtained from interplanetary scintillation (IPS)…
In this paper, I present the results on large-scale evolution of density turbulence of solar wind in the inner heliosphere during 1985 - 2009. At a given distance from the Sun, the density turbulence is maximum around the maximum phase of…
The availability of continuous helioseismic data for two consecutive solar minima has provided a unique opportunity to study the changes in the solar interior that might have led to this unusual minimum. We present preliminary analysis of…
We have measured the physical properties of polar coronal holes from the minimum activity phase of solar cycle 23 (1996-1997) to the present minimum of solar cycle 24 (2007-2009) using the UVCS instrument on SOHO. Observations in H I Lyman…
The ratio of the rms electron density fluctuations to the background density in the solar wind (density modulation index, $\epsilon_{N} \equiv \Delta{N}/N$) is of vital importance in understanding several problems in heliospheric physics…
The variability of helium abundance in the solar corona and the solar wind is an important signature of solar activity, solar cycle, solar wind sources, as well as coronal heating processes. Motivated by recently reported remote sensing UV…
Using data collected by the Indian Mars Orbiter Mission in October 2021, we investigated coronal regions of the Sun by analyzing the Doppler spectral width of radio signals to estimate solar wind velocity. A simplified equation is…
We update the SOHO/SWAN H Lyman-alpha brightness analysis to cover the 1996-2008 time interval. A forward model applied to the intensity maps provides the latitude and time dependence of the interstellar Hydrogen ionisation rate over more…
The extended minimum of Solar Cycle 23, the extremely quiet solar-wind conditions prevailing, and the mini-maximum of Solar Cycle 24 drew global attention and many authors have since attempted to predict the amplitude of the upcoming Solar…
The slow solar wind belt in the quiet corona, observed with the Metis coronagraph on board Solar Orbiter on May 15, 2020, during the activity minimum of the cycle 24, in a field of view extending from 3.8 $R_\odot$ to 7.0 $R_\odot$, is…
Extensive interplanetary scintillation (IPS) observations at 327 MHz obtained between 1983 and 2009 clearly show a steady and significant drop in the turbulence levels in the entire inner heliosphere starting from around ~1995. We believe…
We present a study of the solar wind over different periods of the solar cycle, specifically focussing on the minimum between solar cycles 24 and 25, and the active, ascending phase of solar cycle 25. With the use of interplanetary…
We investigate the characteristics and the sources of the slow (< 450 km/s) solar wind during the four years (2006-2009) of low solar activity between Solar Cycles 23 and 24. We use a comprehensive set of in-situ observations in the…
We analyze data from the Solar and Heliospheric Observatory to produce global maps of coronal outflow velocities and densities in the regions where the solar wind is undergoing acceleration. The maps use UV and white light coronal data…
We present in this Letter the first coordinated radio occultation measurements and ultraviolet observations of the inner corona below 5.5 Rs, obtained during the Galileo solar conjunction in January 1997, to establish the origin of the slow…
We update two kinds of results obtained with the SWAN instrument on board SOHO. First, we use H cell data recorded in 2001 and derive the H flow direction in the same way we performed the study at solar minimum. We compare with the Helium…
Both direct observations and reconstructions from various datasets, suggest that conditions were radically different during the Maunder Minimum (MM) than during the space era. Using an MHD model, we develop a set of feasible solutions to…
The solar minimum 23/24 is considered to be unusual because it exhibits features that differ notably from those commonly seen in pervious minima. In this letter, we analyze the solar polar magnetic field, the potential-field solution of the…
We analyzed intermittency in the solar wind, as observed on the ecliptic plane, looking at magnetic field and velocity fluctuations between 0.3 and 1 AU, for both fast and slow wind and for compressive and directional fluctuations. Our…
Connecting the solar wind observed throughout the heliosphere to its origins in the solar corona is one of the central aims of heliophysics. The variability in the magnetic field, bulk plasma, and heavy ion composition properties of the…