Search Publications
A New Way to Model the Solar Oscillation ℓ−ν Power Spectrum
Jefferies, Stuart M.; Vorontsov, Sergei V.
We present a new approach for the precise and accurate forward modeling of the solar oscillation ℓ−ν power spectrum. The approach is designed to provide the basis for a streamlined solar seismic inversion without measurements of the p-mode frequencies. The new strategy represents a paradigm change in how information is extracted from the oscillati…
Characterization of Intensity Variations Along Fe XIV Coronal Loops - A Case Study
Stenborg, Guillermo; Costa, Andrea
We discuss a method, and corresponding results, to analyze the dynamics of localized small-scale coronal (post-flare) loops observed with the MICA (Mirror Coronagraph for Argentina) telescope in the well-known green coronal line at 530.3 nm. In particular, we designed a procedure to measure intensity variations along the structure of a loop, both …
Total Solar Irradiance Variation During Rapid Sunspot Growth
Fröhlich, Claus; Zahid, H. Jabran; Hudson, Hugh S.
Large sunspot areas correspond to dips in the total solar irradiance (TSI), a phenomenon associated with the local suppression of convective energy transport in the spot region. This results in a strong correlation between sunspot area and TSI. During the growth phase of a sunspot other physics may affect this correlation; if the physical growth o…
Multi-Wavelength Observation Results of the C5.6 Limb Flare of 1 August 2003
Li, Hui; You, Jianqi; Du, Qiusheng +1 more
We obtained a complete set of Hα, Ca Π 8542 å and He I 10830 å spectra and slit-jaw Hα images of the C5.6 limb flare of 1 August 2003 using the Multi-channel Infrared Solar Spectrograph (MISS) at Purple Mountain Observatory. This flare was also observed by the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) and partially by the Extre…
Solar Wind Electron Parameters from ULYSSES/URAP Quasi-Thermal Noise Measurements at Solar Maximum
Issautier, K.; Moncuquet, M.; Hoang, S.
We present the solar wind plasma parameters obtained from the Ulysses spacecraft during its second pole-to-pole fast latitude scan near the 2001 solar maximum. We study the solar wind properties from the electron density and core temperature measurements made by the radio receiver on Ulysses using the method of quasi-thermal noise spectroscopy. We…
Polarization of loop-top and footpoint sources in microwave bursts
Su, Y. N.; Huang, G. L.
The polarization is analyzed in four microwave bursts with one loop-top and two footpoint sources observed at 17 GHz with the Nobeyama Radioheliograph (NoRH). The loop-like structure of the four events is confirmed by simultaneous SOHO/MDI magnetograms and TRACE/EUV images or Yohkoh/SXT images. The heliocentric distance of the four events is great…
Extended search for correlation between solar mean magnetic field BiSON data and coronal mass ejections
Chaplin, William J.; Pintér, Balázs; Elsworth, Yvonne P. +5 more
The Birmingham Solar-Oscillations Network (BiSON) has acquired high-precision solar mean magnetic field (SMMF) data on a 40-s cadence for a decade. We present attempts to compare such data from recent years with the occurrence of coronal mass ejections (CMEs) as recorded by LASCO, using correlation techniques applied to measurements from different…
The Pattern of Moving Magnetic Inhomogeneities in and Around Sunspots
Venkatakrishnan, P.; Kumar, Brajesh; Ravindra, B.
High-resolution MDI magnetograms are used to study the pattern of moving magnetic inhomogeneities in sunspots. We examine the inward and outward moving features in sunspots. The velocity of these features is small in the umbra while it is about 0.5 km s−1 in the outer penumbra. The inward and outward moving features may be the possible …
Comparison of GONG and MDI solar p-mode background
Hill, F.; Barban, C.
Using Severino's model, we estimate the amount of coherent correlated and uncorrelated background and incoherent noise components needed to reproduce the following four helioseismic spectra: V power, I power, V-I phase difference and V-I coherence, using GONG and MDI data. We confirm that a coherent correlated component of 10-15% of the total back…
Absolute Accuracy and Repeatability of the Rmib Radiometers for Tsi Measurements
Mekaoui, Sabri; Dewitte, Steven; Conscience, Christian +3 more
Radiometers for the measurement of the total solar irradiance from space have been developed by D. Crommelynck at the Royal Meteorological Institute of Belgium (RMIB) since 1970. These radiometers, also used in the set of instruments defining the "World Radiometric Reference", have successively flown on SPACELAB 1, ATLAS 1, EURECA, ATLAS 2, ATLAS …