scholarly journals A study of the presence or absence of nitrogen bands in the auroral spectrum

1922 ◽  
Vol 101 (711) ◽  
pp. 312-315 ◽  
Keyword(s):  
Magnetic Disturbance ◽  
Green Line ◽  
The South ◽  
Meteorological Observatory ◽  
Night Sky

In a previous paper I showed that the negative, bands of nitrogen were actually stronger than the green aurora line on the occasion of the auroral display of May 13-14, 1921, which was a typical aurora, in the sense that it was accompanied by conspicuous solar and magnetic disturbance. In contrast with this, the nitrogen bands were not observed at all in the numerous photographs which showed the green line in the night sky on ordinary nights in the south of England. The point deserved much closer scrutiny, as it might be expected to throw light on whether the ordinary night sky effect was to be classed with the northern lights or not. To get additional evidence, I proceeded to Shetland in mid-October, 1921. Dr. G. C. Simpson, F. R. S., and Dr. A. Crichton Mitchell very kindly gave me facilities for working at the meteorological observatory near Lerwick, and Mr. J. Crichton, the officer in charge, did everything possible to help, and continued the exposures throughout the winter after 1 had left. Indeed, all the most successful photographs were taken by him, and forwarded to me for discussion.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

scholarly journals On the spectroscopy of auroral green line radiation

1930 ◽  
Vol 129 (809) ◽  
pp. 31-43 ◽  
Keyword(s):  
High Light ◽  
Green Line ◽  
Light Power ◽  
Line Radiation ◽  
Moonless Night ◽  
Night Sky

In a recent paper by the authors on “Spectroscopy of the Light from the Night Sky,” a description was given of the development and the construction, with optical details, of a high light power spectrograph suitable for photographing the spectrum of the light of the moonless night sky and the spectra of auroral displays. Preliminary experiments were carried out with this instrument in England and in Canada, and a considerable number of spectrograms recorded with the instrument were reproduced and included in the paper.

scholarly journals The aurora line in the spectrum of the night sky

1922 ◽  
Vol 100 (705) ◽  
pp. 367-378 ◽  
Keyword(s):  
Wave Length ◽  
Unknown Origin ◽  
Green Line ◽  
Aurora Borealis ◽  
Low Latitudes ◽  
Good Measurement ◽  
Night Sky

Several observers have found that the green line of unknown origin seen in the Aurora Borealis can also be seen in the sky on ordinary nights, and in comparatively low latitudes. Slipher, in particular, has studied the line photographically, and has succeeded in recording it with a three-prism spectrograph of 15 inches focus, thus obtaining a good measurement of the wave-length.

Coral δ18O records as an indicator of winter monsoon intensity in the South China Sea

2003 ◽  
Vol 59 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Zicheng Peng ◽  
Tegu Chen ◽  
Baofu Nie ◽  
M. John Head ◽  
Xuexian He ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Southern Oscillation ◽  
Winter Monsoon ◽  
The South China Sea ◽  
The South ◽  
Porites Lutea ◽  
China Sea ◽  
Meteorological Observatory ◽  
Monsoon Intensity

AbstractWe have used correlative analysis between mean December–January–February winter wind velocities, measured at the Xisha Meteorological Observatory (16°50′N, 112°20′E) in the middle of the South China Sea, and mean δ18O data for the corresponding month from Porites lutea coral, collected in Longwan waters (19°20′N, 110°39′E), to obtain a linear equation relating the two datasets. This winter wind velocity for the South China Sea (WMIIscs) can then be correlated to the coral δ18O by the equation WMIIscs = −1.213–1.351 δ18O (‰ PDB), r = −0.60, n = 40, P = 0.01. From this, the calculated WMIIscs-δ18O series from 1944 to 1997 tends to decrease during the 1940s to the 1960s; it increases slightly during the 1970s and then decreases again in the 1980s and 1990s. The calculated decadal mean WMIIscs-δ18O series had a obvious decrease from 5.92 to 4.63 m/s during the period of 1944–1997. The calculated yearly mean WMIIscs-δ18O value is 5.58 m/s from 1944 to 1976 and this decreases to 4.85 m/s from 1977 to 1998. That is the opposite trend to the observed yearly mean SST variation. The yearly mean SST anomaly is −0.27° from 1943 to 1976 and this increases to +0.16° from 1977 to 1998. Spectral analysis used on a 54-year-long calculated WMIIscs-δ18O series produces spectral peaks at 2.4–7 yr, which can be closely correlated with the quasibiennial oscillation band (QBO band, 2–2.4 yr) and the El Ñino southern oscillation band (ENSO band, 3–8 yr). Hence most of the variability of the winter monsoon intensity in the middle of the South China Sea is mainly constrained by changes in the thermal difference between the land and the adjoining sea area, perhaps due to global warming.

Review of Aboriginal astronomy and navigation: A Western Australian focus

2021 ◽  
Vol 38 ◽  
Author(s):  
Patricia A. Forster
Keyword(s):  
Real Time ◽  
Western Australia ◽  
Social Behaviour ◽  
Aboriginal Peoples ◽  
The South ◽  
European Settlement ◽  
South West ◽  
Night Sky ◽  
Western Australian

Abstract This review of Aboriginal astronomy and navigation brings together accounts from widely dispersed places in Western Australia, from Noongar Country in the south-west, through to the Eastern Goldfields, the Pilbara, the Kimberley and the Central Deserts. Information for this review has been taken from the literature and non-conventional sources, including artist statements of paintings. The intention for the review is that the scope is traditional, pre-European settlement understandings, but post-settlement records of oral accounts, and later articulation by Aboriginal peoples, are necessarily relied upon. In large part, the Western Australian accounts reflect understandings reported for other states. For example, star maps were used for teaching routes on the ground, but available accounts do not evidence that star maps were used in real-time navigation. The narratives or dreamings that differ most from those of other states explain creation of night-sky objects and landforms on Earth, events including thunder, or they address social behaviour.

A STUDY OF AURORAL MOTIONS FROM ALL-SKY CAMERA RECORDS

1960 ◽  
Vol 38 (10) ◽  
pp. 1279-1290 ◽  
Author(s):  
B. K. Bhattacharyya
Keyword(s):  
Distribution Curve ◽  
Magnetic Disturbance ◽  
The South ◽  
The West ◽  
Systematic Process ◽  
Disturbance Vector ◽  
Two Peaks ◽  
North And South ◽  
East West

A study of horizontal motions of visual aurorae as recorded by a 35-mm all-sky camera at Springhill (geographic 45.2 °N., 75.5 °W.; geomagnetic 56.5 °N., 6.9 °W.) near Ottawa has been carried out. The number of occurrences of motions in all the four geomagnetic directions, east, west, north, and south appears to reach its peak within a range of speed from 0 to 150 m/sec and tends to decrease with increase in speed. Very large speeds seem more frequently to be associated with motions to the west and to the south. The distribution curve of speed with the time of night appears to have two peaks, one before and another after midnight, in all the four cases. Auroral motion is predominantly westward in the early part of the night and eastward in the late hours of the night. The reversal of motion from westward to eastward direction seems to be a systematic process, the declining and inclining portions of the two curves as a function of time meeting each other somewhat before local midnight.Auroral speeds either along or perpendicular to geomagnetic parallels of latitude increase nearly linearly with the horizontal and vertical components of the magnetic disturbance vector.

scholarly journals Absolute intensity of the aurora line in the night sky, and the number of atomic transitions required to maintain it

1930 ◽  
Vol 129 (811) ◽  
pp. 458-467 ◽  
Keyword(s):  
Continuous Spectrum ◽  
Angular Size ◽  
Absolute Intensity ◽  
High Accuracy ◽  
Resolving Power ◽  
Green Line ◽  
Atomic Transitions ◽  
Absolute Determination ◽  
Night Sky

Some time ago Prof. S. Chapman, F. R. S., pressed upon me the importance of making an absolute determination of the intensity of the auroral green line in the night sky, in order to fix the number of atomic transistions per second required to maintain it. Such a determination will be of value even if not of high accuracy value, high accuracy is out of the question. The difficulty of the problem arises from the faintness of the light of the auroral line, and the fact that it is not isolated but superposed on a background of apparently continuous spectrum, from which it cannot in the nature of the case be completely separated without the use of high spectroscopic resolving power. The last usually involves loss of light and restriction of the angular size of the photometric field. There is too little light to begin with to allow of this.

scholarly journals Optical sky brightness at Dome C, Antarctica

2006 ◽  
Vol 2 (14) ◽  
pp. 697-697
Author(s):  
Suzanne L. Kenyon ◽  
John W.V. Storey
Keyword(s):  
South Pole ◽  
The South ◽  
Zodiacal Light ◽  
Atmospheric Extinction ◽  
Astronomical Observations ◽  
Wind Speeds ◽  
Modelling Techniques ◽  
Sky Brightness ◽  
Night Sky

Dome C, Antarctica is a prime site for astronomical observations in terms of climate, wind speeds, turbulence, and infrared and terahertz sky backgrounds (for example, see Aristidi et al. 2005; Storey et al. 2005). However, at present little is known about the optical sky brightness and atmospheric extinction. Using a variety of modelling techniques, together with data from the South Pole, the brightness of the night sky at Dome C is estimated in Kenyon & Storey (2006) including the contributions from scattered sunlight, moonlight, aurorae, airglow, zodiacal light, integrated starlight, diffuse Galactic light and artificial sources. The results are compared to Mauna Kea, Hawaii. We summarise the main conclusions.

Presidential Republicanism in the South, 1960

1962 ◽  
Vol 24 (2) ◽  
pp. 303-322 ◽  
Author(s):  
Bernard Cosman
Keyword(s):  
The South

Periodic Variations in the Coronal Green Line Intensity and their Connection with the White-light Coronal Structures

2000 ◽  
Vol 179 ◽  
pp. 197-200
Author(s):  
Milan Minarovjech ◽  
Milan Rybanský ◽  
Vojtech Rušin
Keyword(s):  
Time Resolution ◽  
White Light ◽  
Short Time Scale ◽  
High Time Resolution ◽  
Green Line ◽  
Periodic Intensity ◽  
Coronal Green Line ◽  
Significant Intensity ◽  
Short Time ◽  
Coronal Structures

AbstractWe present an analysis of short time-scale intensity variations in the coronal green line as obtained with high time resolution observations. The observed data can be divided into two groups. The first one shows periodic intensity variations with a period of 5 min. the second one does not show any significant intensity variations. We studied the relation between regions of coronal intensity oscillations and the shape of white-light coronal structures. We found that the coronal green-line oscillations occur mainly in regions where open white-light coronal structures are located.

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