Antarctic studies of the coupled ionosphere-m agnetosphere system

1989 ◽  
Vol 328 (1598) ◽  
pp. 271-287 ◽  
Keyword(s):  
Solar Wind ◽  
Polar Region ◽  
Experimental Methods ◽  
Future Research ◽  
The South ◽  
Valuable Contribution ◽  
Longitudinal Structure ◽  
The North ◽  
High Latitude Ionosphere ◽  
Per Se

The southern polar region offers many significant advantages over its northern counterpart for studies of the interactions of the solar wind, magnetosphere, ionosphere and thermosphere. These mainly arise from the much wider separation of the geographic and geomagnetic poles in the south compared with the north. These displacements lead to hemispheric asymmetries and to considerable longitudinal structure in the high-latitude ionosphere and magnetosphere, which is particularly striking in the south. Examples of these effects are given. In addition, observations of geospace from Antarctica have made a valuable contribution per se . Suitable illustrations are provided from invariant latitude ca . 45° to the invariant pole. Possible areas for future research, and the experimental methods that are likely to be used to overcome the logistical difficulties, are discussed.

scholarly journals Archaeology of the Gyranda region, Dawson River, central Queensland

1987 ◽  
Vol 4 ◽  
pp. 96-114 ◽  
Author(s):  
M.J. Morwood ◽  
L. Godwin
Keyword(s):  
Water Resources ◽  
Environmental Impact ◽  
Future Research ◽  
Impact Study ◽  
The South ◽  
The West ◽  
The North ◽  
Environmental Impact Study

This paper presents the results of survey and excavation in the upper Dawson area of the Central Queensland Sandstone Belt, a sandstone-dominated environment bounded by the townships of Banana in the east, Blackall in the west, Springsure in the north and Injune in the south, and which includes the Central Queensland Highlands (Walsh 1984:1). The work was undertaken as part of the environmental impact study for the Gyranda Weir commissioned by Cameron McNamara for the Queensland Water Resources Commission (Morwood 1985, 1986; Godwin 1985). However, the results of the study, and the potential of the area for future research, have a wider interest.

scholarly journals Variation of Vitellaria paradoxa phenophases along the north-south gradient in Mali

1970 ◽  
pp. 08-16
Author(s):  
Bokary Allaye Kelly ◽  
Mahesh Poudyal ◽  
Jean-Marc Bouvet
Keyword(s):  
Average Length ◽  
Abiotic Factors ◽  
Permanent Plots ◽  
Future Research ◽  
Vitellaria Paradoxa ◽  
The South ◽  
The North ◽  
Study Sites ◽  
Shea Tree ◽  
Research Challenge

We monitored flowering, fruiting and leafing of Vitellaria paradoxa (shea tree) along the north–south gradient in Mali (West Africa), using three study sites for a period of three years. In each site, adult shea trees were marked and monitored in permanent plots of both field and fallow stands. The chronology of phenophases and their mean length as well as flowering and fruiting were assessed. Our data revealed significant variation according to site and stand. The onset of events starts earlier in the south than in the centre or north, but the period covered by events was almost the same for all sites (3 to 6 months for flowering; 5 to 6 months for fruiting; and 2 to 4 months before full leafing).Flowering and fruiting were more regular in the south, but often as high in the north, with an almost similar trend in both fields and fallows. In the centre, flowering was also high in fields as well as in fallows, while the fruiting was medium to high. We also observed variations in the mean length of phenological events in study sites and stands. Sites in the south showed the highest average length of flowering and leafing (76 days and 44 days, respectively), while the central site showed the greatest length of mean fruiting (110 days).  We observed a significant site*stand interaction and noticeable variation over the years. Our study indicates that phenological events of shea tree could be influenced by several interacting biotic and abiotic factors. A future research challenge in shea phenology would be to discriminate these factors and thus help sustainable management of shea tree parklands.

scholarly journals Solar cycle, seasonal, and asymmetric dependencies of thermospheric mass density disturbances due to magnetospheric forcing

2019 ◽  
Vol 37 (5) ◽  
pp. 989-1003 ◽  
Author(s):  
Andres Calabia ◽  
Shuanggen Jin
Keyword(s):  
Solar Cycle ◽  
High Frequency ◽  
Polar Region ◽  
Rotation Axis ◽  
Mass Density ◽  
Principal Component ◽  
Geomagnetic Variation ◽  
The South ◽  
The North ◽  
Possible Cause

Abstract. Short-term upper atmosphere variations due to magnetospheric forcing are very complex, and neither well understood nor capably modeled due to limited observations. In this paper, mass density variations from 10 years of GRACE observations (2003–2013) are isolated via the parameterization of annual, local solar time (LST), and solar cycle fluctuations using a principal component analysis (PCA) technique. The resulting residual disturbances are investigated in terms of magnetospheric drivers. The magnitude of high-frequency (δ < 10 d) disturbances reveals unexpected dependencies on the solar cycle, seasonal, and an asymmetric behavior with smaller amplitudes in June in the south polar region (SPR). This seasonal modulation might be related to the Russell–McPherron (RM) effect. Meanwhile, we find a similar pattern, although less pronounced, in the northern and equatorial regions. A possible cause of this latitudinal asymmetry might be the irregular shape of the Earth's magnetic field (with the north dip pole close to Earth's rotation axis, and the south dip pole far from that axis). After accounting for the solar cycle and seasonal dependencies by regression analysis to the magnitude of the high-frequency perturbations, the parameterization in terms of the disturbance geomagnetic storm-time index Dst shows the best correlation, whereas the geomagnetic variation Am index and merging electric field Em are the best predictors in terms of time delay. We test several mass density models, including JB2008, NRLMSISE-00, and TIEGCM, and find that they are unable to completely reproduce the seasonal and solar cycle trends found in this study, and show a clear overestimation of about 100 % during low solar activity periods.

The Marlborough Mound, Wiltshire. A Further Neolithic Monumental Mound by the River Kennet

2013 ◽  
Vol 79 ◽  
pp. 137-163 ◽  
Author(s):  
Jim Leary ◽  
Matthew Canti ◽  
David Field ◽  
Peter Fowler ◽  
Peter Marshall ◽  
...  
Keyword(s):  
Future Research ◽  
Small Scale ◽  
Main Body ◽  
Soil Cores ◽  
Flood Events ◽  
The South ◽  
Late Neolithic ◽  
Radiocarbon Dates ◽  
North East ◽  
The North

Recent radiocarbon dates obtained from two soil cores taken through the Marlborough Castle mound, Wiltshire, show the main body of it to be a contemporaneous monument to Silbury Hill, dating to the second half of the 3rd millennium cal bc. In light of these dates, this paper considers the sequence identified within the cores, which includes two possible flood events early in the construction of the mound. It also describes four cores taken through the surrounding ditch, as well as small-scale work to the north-east of the mound. The topographic location of the mound in a low-lying area and close to rivers and springs is discussed, and the potential for Late Neolithic sites nearby is set out, with the land to the south of the mound identified as an area for future research. The paper ends with the prospect that other apparent mottes in Wiltshire and beyond may well also have prehistoric origins

Understanding the Roots of War

2018 ◽  
Author(s):  
Paul D. Escott
Keyword(s):  
African Americans ◽  
Future Research ◽  
New Work ◽  
Economic Perspective ◽  
The South ◽  
The North ◽  
Sectional Conflict

This chapter focuses on the sectional conflict leading to war. It reviews changing interpretive approaches before focusing on new work that often takes a global or Atlantic and primarily economic perspective. It raises many questions that may usefully inspire future research. The South, the North, and the “middle” or “border” third of the nation receive attention, as do African Americans and popular attitudes toward the nation.

The Thames as a Barrier in the Eighteenth Century

2018 ◽  
pp. 26-46
Author(s):  
Derek Morris ◽  
Ken Cozens
Keyword(s):  
Eighteenth Century ◽  
Future Research ◽  
The South ◽  
Tower Of London ◽  
Migration Patterns ◽  
Major Barrier ◽  
Insurance Policies ◽  
The North ◽  
Business Opportunities ◽  
North Bank

Analysis of marriage registers, apprentice records, wills and insurance policies demonstrates that in the eighteenth century, the Thames, downstream from the Tower of London, was a major barrier to the development of strong business and marriage links between the residents on the north bank in Stepney, and those on the south bank in Surrey and Kent. Possible reasons for our findings are examined in the context of London's growth, migration patterns and business opportunities. The importance of Sun Fire Office insurance policies, in examining personal and commercial links between places far apart is emphasised. Suggestions are made for future research.

The evolution of Jupiter polar cyclones

2021 ◽  
Author(s):  
Alessandro Mura ◽  
Christina Plainaki ◽  
Giuseppe Sindoni ◽  
Alberto Adriani ◽  
Davide Grassi ◽  
...  
Keyword(s):  
Polar Region ◽  
Infrared Camera ◽  
Polar Regions ◽  
The South ◽  
The North ◽  
Rest Position ◽  
North Polar ◽  
The Stability ◽  
Westward Drift ◽  
Juno Mission

&lt;p&gt;JIRAM (the Jovian InfraRed Auroral Mapper) is an infrared camera and&lt;br&gt;spectrometer on board Juno. JIRAM operates in the 2-5 &amp;#956;m spectral&lt;br&gt;range and is built to observe both Jupiter's infrared aurora and its&lt;br&gt;atmosphere. Since 2016, JIRAM has performed several observations of&lt;br&gt;the polar regions of the planet, thanks to the unique orbital design&lt;br&gt;of the Juno mission.&amp;#160; In the north polar region, Juno discovered, in&lt;br&gt;2017, the presence of an eight-cyclone structure around a single polar&lt;br&gt;cyclone; to the south, a polar cyclone is surrounded by five&lt;br&gt;circumpolar cyclones. The stability of these structures has been&lt;br&gt;monitored for almost 4 years. Recent observations, made at the end of&lt;br&gt;2019, showed that the configuration of the South Pole has temporarily&lt;br&gt;changed: the structure moved in a hexagon for a few months, before&lt;br&gt;returning to its original pentagonal shape. To the north, there are&lt;br&gt;significant hints that the octagonal shape may have been lost for a&lt;br&gt;similar period of time.&lt;br&gt;We find that all cyclones show a very slow, westward drift as a rigid&lt;br&gt;ensemble, and, in addition, they oscillate around their rest position&lt;br&gt;with similar timescales. These oscillations seem to propagate from&lt;br&gt;cyclone to cyclone. The implications of these transient deviations&lt;br&gt;from the symmetrical forms, which appear to be an apparent condition&lt;br&gt;of equilibrium, are discussed.&lt;/p&gt;

scholarly journals Reflections on the Other Side. A Southern Iberia Origin for the First Pottery Production of Northern Morocco?

2021 ◽  
Vol 7 (1) ◽  
pp. 1054-1065
Author(s):  
Rafael M. Martínez Sánchez ◽  
Juan Carlos Vera Rodríguez ◽  
Jesús Gámiz Caro ◽  
Salvador Pardo-Gordó ◽  
Guillem Pérez-Jordà ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
The Other ◽  
Future Research ◽  
Pottery Production ◽  
The South ◽  
The North ◽  
Starting Point ◽  
Southern Iberia

Abstract This work is a starting point for rethinking the role of the Iberian Peninsula in the neolithisation of northern Morocco. It focuses on the similarities and divergences between the first pottery productions and their decorations in both territories. This relationship is supported by the existence of an accurate chronological gradation between the first evidence of Neolithisation in Iberian Peninsula and that of northern Morocco which suggests a north–south direction. We also present arguments on the possible links between the early ceramics from the north of Morocco and those from the south of Iberia, providing a first approach to an issue that will need to be carefully analysed in future research.

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.

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