DETECTION OF SUPERGRANULATION ALIGNMENT IN POLAR REGIONS OF THE SUN BY HELIOSEISMOLOGY

Abstract. In 2000–2001 Ulysses passed from the south to the north polar regions of the Sun in the inner heliosphere, providing a snapshot of the latitudinal structure of cosmic ray modulation and solar energetic particle populations during a period near solar maximum. Observations from the COSPIN suite of energetic charged particle telescopes show that latitude variations in the cosmic ray intensity in the inner heliosphere are nearly non-existent near solar maximum, whereas small but clear latitude gradients were observed during the similar phase of Ulysses’ orbit near the 1994–95 solar minimum. At proton energies above ~10 MeV and extending up to >70 MeV, the intensities are often dominated by Solar Energetic Particles (SEPs) accelerated near the Sun in association with intense solar flares and large Coronal Mass Ejections (CMEs). At lower energies the particle intensities are almost constantly enhanced above background, most likely as a result of a mix of SEPs and particles accelerated by interplanetary shocks. Simultaneous high-latitude Ulysses and near-Earth observations show that most events that produce large flux increases near Earth also produce flux increases at Ulysses, even at the highest latitudes attained. Particle anisotropies during particle onsets at Ulysses are typically directed outwards from the Sun, suggesting either acceleration extending to high latitudes or efficient cross-field propagation somewhere inside the orbit of Ulysses. Both cosmic ray and SEP observations are consistent with highly efficient transport of energetic charged particles between the equatorial and polar regions and across the mean interplanetary magnetic fields in the inner heliosphere.Key words. Interplanetary physics (cosmic rays) – Solar physics, astrophysics and astronomy (energetic particles; flares and mass ejections)

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1.1.13 A Temporal Study of the Radiance of the F-Corona Close to the Sun

International Astronomical Union Colloquium ◽

10.1017/s0252921100051423 ◽

1976 ◽

Vol 31 ◽

pp. 65-65

Author(s):

R.H. Munro

Keyword(s):

Temporal Variations ◽

Stray Light ◽

Polar Regions ◽

The Sun ◽

Photometric Calibration ◽

Temporal Study ◽

Single Region ◽

Solar Eruptions ◽

The Individual ◽

Source Of Error

During the Skylab mission – May 1973 through February 1974 – the High Altitude Observatory’s white light coronagraph observed the sum of the F-corona, electron scattered K-corona, and instrumental stray light between 0.4 and 1.6 degrees from the sun. In searching for temporal variations in the F-corona, measurements were confined to the solar polar regions to minimize the effects of the K-coronal component. Changes in instrumental stray light were eliminated by restricting measurements to a single region within the instruments’ field of view. The largest source of error is the photometric calibration of the individual rolls of film. Frames were specifically selected to encompass periods of time ranging from a few days to eight months. Generally no variation in the total radiance greater than three percent was detected for intervals on the order of a few weeks. This level of stability holds for most of the eight-month period, excepting a few instances when deviations of up to eight percent were observed where the calibration is most uncertain. A preliminary study of the asymmetry in the F-corona close to the sun and the possible effect of solar eruptions (e.g., flares and prominences) upon the F-corona will be discussed.

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The Solar Orbiter mission – Exploring the Sun and heliosphere

10.5194/egusphere-egu21-2981 ◽

2021 ◽

Author(s):

Daniel Mueller ◽

Yannis Zouganelis ◽

Teresa Nieves-Chinchilla ◽

Chris St. Cyr

Keyword(s):

High Spatial Resolution ◽

Ecliptic Plane ◽

Space Mission ◽

Polar Regions ◽

The Sun ◽

Very High Spatial Resolution ◽

New Perspective ◽

Orbiter Mission ◽

Very High

Solar Orbiter, launched on 10 February 2020, is a space mission of international collaboration between ESA and NASA. It is exploring the linkage between the Sun and the heliosphere and has started to collect unique data at solar distances down to 0.49 AU. By ultimately approaching as close as 0.28 AU, Solar Orbiter will view the Sun with very high spatial resolution and combine this with in-situ measurements of the surrounding heliosphere. Over the course of the mission, the highly elliptical orbit will get progressively more inclined to the ecliptic plane. Thanks to this new perspective, Solar Orbiter will deliver images and comprehensive data of the unexplored Sun&#8217;s polar regions and the side of the Sun not visible from Earth. This talk will highlight first science results from Solar Orbiter and provide a mission status update.

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Solar Orbiter: Europe's mission to the Sun

10.5194/egusphere-egu2020-22164 ◽

2020 ◽

Author(s):

Yannis Zouganelis ◽

Daniel Mueller ◽

Chris St Cyr ◽

Holly Gilbert ◽

Teresa Nieves-Chinchilla

Keyword(s):

High Spatial Resolution ◽

Solar Wind Plasma ◽

Ecliptic Plane ◽

Current Status ◽

Polar Regions ◽

The Sun ◽

Physical Processes ◽

New Perspective ◽

Orbiter Mission

ESA&#8217;s Solar Orbiter mission is scheduled for launch in February 2020, and will focus on exploring the linkage between the Sun and the heliosphere. It is a collaborative mission with NASA that will collect unique data that will allow us to study, e.g., the coupling between macroscopic physical processes to those on kinetic scales, the generation of solar energetic particles and their propagation into the heliosphere, and the origin and acceleration of solar wind plasma. By approaching as close as 0.28 AU, Solar Orbiter will view the Sun with high spatial resolution and combine this with in-situ measurements of the surrounding heliosphere. Over the course of the mission, the highly elliptical orbit will get progressively more inclined to the ecliptic plane. Thanks to this new perspective, Solar Orbiter will deliver images and comprehensive data of the unexplored Sun&#8217;s polar regions and the side of the Sun not visible from Earth. This talk will provide a mission overview, highlight synergies with NASA&#8217;s Parker Solar Probe and summarise current status.

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The increase in the magnetic flux from the polar regions of the Sun over the last 120 years

Astronomy Reports ◽

10.1134/1.1398924 ◽

2001 ◽

Vol 45 (9) ◽

pp. 746-750 ◽

Cited By ~ 3

Author(s):

V. I. Makarov ◽

V. N. Obridko ◽

A. G. Tlatov

Keyword(s):

Magnetic Flux ◽

Polar Regions ◽

The Sun

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Cosmic Ray and Solar Particle Investigations Over the South Polar Regions of the Sun

Science ◽

10.1126/science.268.5213.1019 ◽

1995 ◽

Vol 268 (5213) ◽

pp. 1019-1023 ◽

Cited By ~ 62

Author(s):

J. A. Simpson ◽

J. J. Connell ◽

C. Lopate ◽

R. B. McKibben ◽

M. Zhang ◽

...

Keyword(s):

Cosmic Ray ◽

Polar Regions ◽

The Sun ◽

The South ◽

Solar Particle ◽

South Polar

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Mars

Photochemistry of Planetary Atmospheres ◽

10.1093/oso/9780195105018.003.0010 ◽

1999 ◽

Author(s):

Yuk L. Yung ◽

William B. DeMore

Keyword(s):

Seasonal Variation ◽

Water Vapor ◽

Mass Spectrum ◽

Martian Atmosphere ◽

Dust Storms ◽

Polar Regions ◽

The Sun ◽

Incident Solar Radiation ◽

The Mean ◽

Pressure Changes

Mars has been extensively studied by a series of spacecraft since the dawn of the space age: by Mariners 4, 6, 7, and 9 (1965-1972), Mars 2 through 6 (1971-1974), and the two Viking Landers and Orbiters in 1976. The knowledge from spacecraft is supplemented by ground-based observations. The essential aspects of Mars are summarized in table 7.1. It is a smaller planet than Earth; the radius and mass are, respectively, 53% and 11% of Earth. The surface gravity is 3.71 m s~2, compared with the terrestrial value of 9.82 m s~2. The physical properties and composition of the Martian atmosphere are summarized in tables 7.1 and 7.2; isotopic composition is given in table 7.3. An example of how this knowledge is obtained is illustrated in figure 7.1, showing the mass spectrum obtained by the mass spectrometer experiment on Viking. The bulk atmosphere is composed of CO2, with small amounts of N2 and Ar and a trace amount of water vapor. Located at 1.52 AU from the sun, the mean insolation at Mars is about half that of Earth. As a result, it is a colder planet, with mean surface temperature of 220 K, too cold for water to flow on the surface in the current epoch. The lack of an ocean results in an arid and dusty climate. The obliquity of Mars is 25.2°, close to the terrestrial value of 23.5°; however, Mars has an eccentric orbit, with eccentricity of 0.093. The ratio of incident solar radiation at perihelion to aphelion is 1.45. The large seasonal variation in heating is believed to be responsible for the spectacular global dust storms that can be observed from Earth and have inspired imaginative but erroneous theories about their origin. The polar regions of Mars can be as cold as 125 K, so CO2 will condense as frost on the surface. In fact, according to the Leighton-Murray model, this is what determines the pressure of the atmosphere. Figure 7.2 shows the seasonal pressure variations at the Viking lander sites for 3.3 Mars years from 1976. Note that the magnitude of the pressure changes is of the order of 20%, compared to the maximum change of 1% on the surface of Earth.

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The Magnetic Fields of Pulsars, Electrons and the Sun

Publications of the Astronomical Society of Australia ◽

10.1017/s1323358000019408 ◽

1992 ◽

Vol 10 (2) ◽

pp. 110-112

Author(s):

K. D. Cole

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Magnetic Energy ◽

Rest Mass ◽

Building Blocks ◽

Polar Regions ◽

The Sun ◽

Electron Positron ◽

Celestial Bodies ◽

Electron Gyrofrequency

AbstractAn apparent connection is reported between the magnetic field strengths inside an electron, in newly born pulsars, and the sun. It is argued that the upper limit to the strength of magnetic field which seems to exist is that which would permit emission of a photon at the non-relativistic electron gyrofrequency, with energy of the order of the electron rest mass. The strongest magnetic fields at the surface of polar regions of pulsars conform to this. By equating approximately the rest mass of an electron to its magnetic energy, the same magnetic field is found inside the electron. It is proposed that magnetic field building ‘blocks’ called M-particles are formed by a variant of the electron-positron spin-zero annihilation. The particles become as tightly stacked as possible to form the macroscopic magnetic field of the newly born pulsar. The sun’s present magnetic moment is described by a pulsar-sized object at its centre, with the maximum packing of M-particles. The hypothesis may have a bearing on the formation of magnetic fields in celestial bodies, and on the secular variation of the magnetic fields of the sun and the Earth.

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