相关论文: Element Abundances: A New Diagnostic for the Solar…
We find that the element abundances in solar energetic particles (SEPs) and in the slow solar wind (SSW), relative to those in the photosphere, show different patterns as a function of the first ionization potential (FIP) of the elements.…
The First Ionization Potential (FIP) effect is the by now well known enhancement in abundance over photospheric values of Fe and other elements with first ionization potential below about 10 eV observed in the solar corona and slow speed…
Elemental abundances in the solar corona and solar wind are often observed to differ from those in the solar photosphere, most commonly showing an enhancement of low first ionization-potential (FIP) elements (the FIP effect). The…
We present an examination of the First Ionization Potential (FIP) fractionation scenario invoking the ponderomotive force in the chromosphere, and its implications for the source(s) of slow speed solar winds by using observations from The…
We review our state of knowledge of coronal element abundance anomalies in the Sun and stars. We concentrate on the first ionization potential (FIP) effect observed in the solar corona and slow-speed wind, and in the coronae of solar-like…
We revisit in more detail a model for element abundance fractionation in the solar chromosphere, that gives rise to the "FIP Effect" in the solar corona and wind. Elements with first ionization potential below about 10 eV, i.e. those that…
The elemental composition of the solar wind differs from the solar photospheric composition. Elements with low first ionization potential (FIP) appear enhanced compared to O in the solar wind relative to the respective photospheric…
Elemental abundances in the solar corona are known to be different from those observed in the solar photosphere. The ratio of coronal to photospheric abundance shows a dependence on the first ionisation potential (FIP) of the element. We…
The relative abundances of chemical elements and isotopes have been our most effective tool in identifying and understanding energetic particles. The early surprise in solar energetic particles (SEPs) was 1000-fold enhancements in 3He/4He…
Elemental abundances in solar flares are observed to vary both spatially and temporally, but the underlying mechanisms remain poorly understood. There is an interplay between advection and the preferential acceleration of low first…
The Inverse First Ionization Potential (FIP) Effect, the depletion in coronal abundance of elements like Fe, Mg, and Si that are ionized in the solar chromosphere relative to those that are neutral, has been identified in several solar…
The chemical composition of solar and stellar atmospheres differs from that of their photospheres. Abundances of elements with low first ionization potential (FIP) are enhanced in the corona relative to high FIP elements with respect to the…
The origin of the slow solar wind is not well understood, unlike the fast solar wind which originates from coronal holes. In-situ elemental abundances of the slow solar wind suggest that it originates from initially closed field lines that…
The enrichment of coronal loops and the slow solar wind with elements that have low First Ionisation Potential, known as the FIP effect, has often been interpreted as the tracer of a common origin. A current explanation for this FIP…
The solar corona shows a distinctive pattern of elemental abundances that is different from that of the photosphere. Low first ionization potential (FIP) elements are enhanced by factors of several. A similar effect is seen in the…
We outline and discuss a model for the enhanced abundances of trans-Fe elements in impulsive Solar Energetic Particle (SEP) events, where large mass dependent abundance enhancements are frequently seen. It comes about as a variation of the…
The abundances of low First Ionisation Potential (FIP) elements are three to four times higher (FIP bias) in the closed loop active corona than in the photosphere, known as the FIP effect. Observations suggest that the abundances vary in…
A model for element abundance fractionation between the solar chromosphere and corona is further developed. The ponderomotive force due to Alfven waves propagating through, or reflecting from the chromosphere in solar conditions generally…
Elemental abundances in the solar corona differ from those in the photosphere, with low first ionization potential (FIP) elements being enhanced, a phenomenon known as the FIP effect. This enhancement is attributed to ponderomotive forces…
From a turbulent history, the study of abundances of elements in solar energetic particles (SEPs) has grown into an extensive field that probes the solar corona and the physical processes of SEP acceleration and transport. Underlying SEPs…