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

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.

Chimeras In Time-Honored Societies

Think India ◽  
2019 ◽  
Vol 22 (2) ◽  
pp. 463-466
Author(s):  
TUMMALA. SAI MAMATA
Keyword(s):  
Major Elements ◽  
The Sun ◽  
Human Beings ◽  
Life Changes ◽  
Inner Self ◽  
The World ◽  
Nature And Nurture ◽  
The Individual ◽  
The Right ◽  
Superstitious Beliefs

A river flows serenely accepting all the miseries and happiness that it comes across its journey. A tree releases oxygen for human beings despite its inner plights. The sun is never tired of its duty and gives sunlight without any interruption. Why are all these elements of nature so tuned to? Education is knowledge. Knowledge comes from learning. Learning happens through experience. Familiarity is the master of life that shapes the individual. Every individual learns from nature. Nature teaches how to sustain, withdraw and advocate the prevailing situations. Some dwell into the deep realities of nature and nurture as ideal human beings. Life is a puzzle. How to solve it is a million dollar question that can never be answered so easily. The perception of life changes from individual to individual making them either physically powerful or feeble. Society is not made of only individuals. Along with individuals it has nature, emotions, spiritual powers and superstitious beliefs which bind them. Among them the most crucial and alarming is the emotions which are interrelated to others. Alone the emotional intelligence is going to guide the life of an individual. For everyone there is an inner self which makes them conscious of their deeds. The guiding force should always force the individual to choose the right path.  Writers are the powerful people who have rightly guided the society through their ingenious pen outs.  The present article is going to focus on how the major elements bound together are dominating the individual’s self through Rabindranath Tagore’s Home and the World (1916)

Rotation of the magnetic elements in polar regions on the Sun

2007 ◽  
Vol 328 (10) ◽  
pp. 1016-1019 ◽  
Author(s):  
E.E. Benevolenskaya
Keyword(s):  
Polar Regions ◽  
The Sun ◽  
Magnetic Elements

scholarly journals Ulysses COSPIN observations of cosmic rays and solar energetic particles from the South Pole to the North Pole of the Sun during solar maximum

2003 ◽  
Vol 21 (6) ◽  
pp. 1217-1228 ◽  
Author(s):  
R. B. McKibben ◽  
J. J. Connell ◽  
C. Lopate ◽  
M. Zhang ◽  
J. D. Anglin ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Solar Maximum ◽  
Cosmic Ray ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Polar Regions ◽  
The Sun ◽  
The South ◽  
The North ◽  
Inner Heliosphere

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)

Error Analysis of a Mobile Terrestrial LiDAR System

GEOMATICA ◽  
2014 ◽  
Vol 68 (3) ◽  
pp. 183-194 ◽  
Author(s):  
M. Leslar ◽  
B. Hu ◽  
J.G. Wang
Keyword(s):  
Point Cloud ◽  
Point Clouds ◽  
Sensitivity Study ◽  
Error Sources ◽  
Terrestrial Lidar ◽  
Lever Arm ◽  
Ideal Situation ◽  
Individual Variables ◽  
The Individual ◽  
Source Of Error

The understanding of the effects of error on Mobile Terrestrial LiDAR (MTL) point clouds has not increased with their popularity. In this study, comprehensive error analyses based on error propagation theory and global sensitivity study were carried out to quantitatively describe the effects of various error sources in a MTL system on the point cloud. Two scenarios were envisioned; the first using the uncertainties for measurement and calibration variables that are normally expected for MTL systems as they exist today, and the second using an ideal situation where measurement and calibration values have been well adjusted. It was found that the highest proportion of error in the point cloud can be attributed to the boresight and lever arm parameters for MTL systems calibrated using non-rigours methods. In particular, under a loosely controlled error condition, the LiDAR to INS Z lever arm and the LiDAR to INS roll angle contributed more error in the output point cloud than any other parameter, including the INS position. Under tightly controlled error conditions, the INS position became the dominant source of error in the point cloud. In addition, conditional variance analysis has shown that the majority of the error in a point cloud can be attributed to the individual variables. Errors caused by the interactions between the diverse variables are minimal and can be regarded as insignificant.

scholarly journals Aurora and open magnetic flux during isolated substorms, sawteeth, and SMC events

2007 ◽  
Vol 25 (8) ◽  
pp. 1865-1876 ◽  
Author(s):  
A. D. DeJong ◽  
X. Cai ◽  
R. C. Clauer ◽  
J. F. Spann
Keyword(s):  
Magnetic Flux ◽  
Temporal Variations ◽  
Auroral Oval ◽  
Polar Cap ◽  
Expansion Phase ◽  
Magnetospheric Convection ◽  
Open Magnetic Flux ◽  
Open Flux ◽  
The Individual

Abstract. Using Polar UVI LBHl and IMAGE FUV WIC data, we have compared the auroral signatures and polar cap open flux for isolated substorms, sawteeth oscillations, and steady magnetospheric convection (SMC) events. First, a case study of each event type is performed, comparing auroral signatures and open magnetic fluxes to one another. The latitude location of the auroral oval is similar during isolated substorms and SMC events. The auroral intensity during SMC events is similar to that observed during the expansion phase of an isolated substorm. Examination of an individual sawtooth shows that the auroral intensity is much greater than the SMC or isolated substorm events and the auroral oval is displaced equatorward making a larger polar cap. The temporal variations observed during the individual sawtooth are similar to that observed during the isolated substorm, and while the change in polar cap flux measured during the sawtooth is larger, the percent change in flux is similar to that measured during the isolated substorm. These results are confirmed by a statistical analysis of events within these three classes. The results show that the auroral oval measured during individual sawteeth contains a polar cap with, on average, 150% more magnetic flux than the oval measured during isolated substorms or during SMC events. However, both isolated substorms and sawteeth show a 30% decrease in polar cap magnetic flux during the dipolarization (expansion) phase.

scholarly journals The Solar Orbiter Science Activity Plan

2020 ◽  
Vol 642 ◽  
pp. A3 ◽  
Author(s):  
I. Zouganelis ◽  
A. De Groof ◽  
A. P. Walsh ◽  
D. R. Williams ◽  
D. Müller ◽  
...  
Keyword(s):  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Coronal Magnetic Field ◽  
Space Mission ◽  
The Sun ◽  
Particle Radiation ◽  
Science Activity ◽  
Science Operations ◽  
Solar Eruptions

Solar Orbiter is the first space mission observing the solar plasma both in situ and remotely, from a close distance, in and out of the ecliptic. The ultimate goal is to understand how the Sun produces and controls the heliosphere, filling the Solar System and driving the planetary environments. With six remote-sensing and four in-situ instrument suites, the coordination and planning of the operations are essential to address the following four top-level science questions: (1) What drives the solar wind and where does the coronal magnetic field originate?; (2) How do solar transients drive heliospheric variability?; (3) How do solar eruptions produce energetic particle radiation that fills the heliosphere?; (4) How does the solar dynamo work and drive connections between the Sun and the heliosphere? Maximising the mission’s science return requires considering the characteristics of each orbit, including the relative position of the spacecraft to Earth (affecting downlink rates), trajectory events (such as gravitational assist manoeuvres), and the phase of the solar activity cycle. Furthermore, since each orbit’s science telemetry will be downloaded over the course of the following orbit, science operations must be planned at mission level, rather than at the level of individual orbits. It is important to explore the way in which those science questions are translated into an actual plan of observations that fits into the mission, thus ensuring that no opportunities are missed. First, the overarching goals are broken down into specific, answerable questions along with the required observations and the so-called Science Activity Plan (SAP) is developed to achieve this. The SAP groups objectives that require similar observations into Solar Orbiter Observing Plans, resulting in a strategic, top-level view of the optimal opportunities for science observations during the mission lifetime. This allows for all four mission goals to be addressed. In this paper, we introduce Solar Orbiter’s SAP through a series of examples and the strategy being followed.

scholarly journals Spatial and Temporal Variations in Pigment and Species Compositions of Snow Algae on Mt. Tateyama in Toyama Prefecture, Japan

2021 ◽  
Vol 12 ◽  
Author(s):  
Tomomi Nakashima ◽  
Jun Uetake ◽  
Takahiro Segawa ◽  
Lenka Procházková ◽  
Akane Tsushima ◽  
...  
Keyword(s):  
High Performance ◽  
Algal Species ◽  
High Performance Liquid Chromatographic ◽  
Temporal Variations ◽  
Algal Community ◽  
Rrna Gene ◽  
Polar Regions ◽  
Dominant Type ◽  
Content Type ◽  
Snow Algae

Snow algae are photosynthetic microbes that inhabit the melting snow surface in alpine and polar regions. We analyzed the pigment and species composition of colored snow collected on Mt. Tateyama in Japan during the melting seasons of 2015 and 2016. High-performance liquid chromatographic analyses of the pigments extracted from the colored snow showed that their composition varied within the study area and were classified into four types: Type A (astaxanthin-monoester dominant), Type B (medium astaxanthin-monoester content), Type C (abundant primary carotenoids and free-astaxanthin), and Type D (abundant primary carotenoids and astaxanthin diesters). Types A and B were most commonly observed in the study area, whereas Types C and D appeared only at specific sites. Analysis of the 18S ribosomal RNA (18S rRNA) gene revealed six major amplicon sequence variants (ASVs) of snow algae, belonging to the Sanguina, Chloromonas, and Chlainomonas groups. The relative abundance of the algal ASVs showed that Sanguina was dominant (>48%) in both Types A and B, suggesting that the difference in astaxanthin abundance between the two types was caused by the production of pigments in the algal cells. The algal community structures of Types C and D differed from those of Types A and B, indicating that the primary carotenoids and astaxanthin diesters were derived from certain algal species in these types. Therefore, astaxanthin-rich Sanguina algae mostly induced the red snow that appeared widely in this alpine area; however, they were partially dominated by Chloromonas or Chlainomonas algae, causing different pigment compositions.

scholarly journals Intra-seasonal oscfffations of radio refractive index during southwest monsoon over India

MAUSAM ◽  
2022 ◽  
Vol 44 (3) ◽  
pp. 271-276
Author(s):  
H. N. SRIVASTAVA ◽  
K. C. SINHARAY ◽  
R. K. MUKHOPADHYAY
Keyword(s):  
Refractive Index ◽  
Monsoon Season ◽  
Temporal Variations ◽  
Southwest Monsoon ◽  
The Individual ◽  
Southwest Monsoon Season ◽  
Seasonal Oscillations ◽  
Refractive Index Data ◽  
Indian Seas ◽  
Variance Explained

The study deals with the spatial and temporal variations of intra-seasonal oscillations in radio refractive index during southwest monsoon season over India and islands over Indian seas. Average daily radio refractive index data from 1 June to 30 September and that of the individual years for the period 1969-1986 were subjected to harmonic analysis to investigate the contributions of various periodicities in monsoon radio refractive index. The inter-annual variability of various intra-seasonal oscillations have been studied for each 5° latitudinal strip from 50 oN to 30° N with the help of variance explained by various frequency modes for different years. Variance explained by 30-60 day and 10-20 day modes were studied in relation to monsoon performance.   The northward and eastward propagation of30.60 day mod~ was noticed. The 10.20 day mode and seasonal mode dominate at latitudinal belts 5°N.10oN and 25°N-30°N respectively. Between 10°N and 25°N, both 30-60 day and 10-20 day modes occur.  

scholarly journals Linking atmospheric pollution to cryospheric change in the Third Pole region: current progress and future prospects

2019 ◽  
Vol 6 (4) ◽  
pp. 796-809 ◽  
Author(s):  
Shichang Kang ◽  
Qianggong Zhang ◽  
Yun Qian ◽  
Zhenming Ji ◽  
Chaoliu Li ◽  
...  
Keyword(s):  
Atmospheric Pollution ◽  
Environmental Changes ◽  
Temporal Variations ◽  
Global Perspective ◽  
Atmospheric Pollutants ◽  
Future Research ◽  
The Tibetan Plateau ◽  
Polar Regions ◽  
Research Framework ◽  
The Third

ABSTRACTThe Tibetan Plateau and its surroundings are known as the Third Pole (TP). This region is noted for its high rates of glacier melt and the associated hydrological shifts that affect water supplies in Asia. Atmospheric pollutants contribute to climatic and cryospheric changes through their effects on solar radiation and the albedos of snow and ice surfaces; moreover, the behavior and fates within the cryosphere and environmental impacts of environmental pollutants are topics of increasing concern. In this review, we introduce a coordinated monitoring and research framework and network to link atmospheric pollution and cryospheric changes (APCC) within the TP region. We then provide an up-to-date summary of progress and achievements related to the APCC research framework, including aspects of atmospheric pollution's composition and concentration, spatial and temporal variations, trans-boundary transport pathways and mechanisms, and effects on the warming of atmosphere and changing in Indian monsoon, as well as melting of glacier and snow cover. We highlight that exogenous air pollutants can enter into the TP’s environments and cause great impacts on regional climatic and environmental changes. At last, we propose future research priorities and map out an extended program at the global scale. The ongoing monitoring activities and research facilitate comprehensive studies of atmosphere–cryosphere interactions, represent one of China's key research expeditions to the TP and the polar regions and contribute to the global perspective of earth system science.

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