Post-midnight equatorial scintillation activity in relation to geomagnetic disturbances

VHF amplitude scintillation measurements made during the period April 1978 through December 1982 at Calcutta (23°N, 88.5°E; 32°N dip), situated near the northern crest of the Appleton Anomaly in the Indian sector, have been used to study the association of post-midnight (as well as post-sunrise) scintillations with the occurrences of the maximum negative excursion in the variation of the Earth's horizontal magnetic intensity. The post-midnight scintillation has been found to be related to the maximum negative excursion occurring in the 0000–0600 LT interval. No such relation is observed with the pre-midnight excursions. Scintillation with onset between 0000 and 0300 LT shows remarkable correspondence with the occurrence of negative excursion (18 out of 20 available cases). Magnetic conditions with Dst < −150 nT have been found to be most effective in producing the above scintillation activity. From the present observations, a threshold value of the maximum negative excursion of Dst for producing scintillation may be obtained, Dst < −75 nT being significantly associated with the post-midnight scintillation occurrences. The results are interpreted in terms of the reversal of the equatorial horizontal electric field, under magnetically disturbed conditions, due to a coupling of the high latitude and magnetospheric current systems with the equatorial electric field.     

The late prehistory of xinjiang in relation to its neighbors

Recent research by Chinese archaeologists has identified many late prehistoric (2000-400 B.C.) oases, pastoral settlements, and cemeteries in eastern Central Asia (Xinjiang province of China). The synthesis presented here organizes the data into 10 archaeological cultures, defined on the basis of ceramics, burials, small finds, and architecture. The archaeological cultures reveal two periods, corresponding to the Bronze Age and the Iron Age. The oases cultures formed a core area before the Chinese Han period and maintained close contacts with nearby highland pastoralists in Siberia and western Central Asia. The evidence for interaction between Xinjiang and the complex cultures in China and western Central Asia is evaluated with regard to the origins of the early Xinjiang cultures.     

NDVI variation and its relation to climate in Canadian ecozones

Parks Canada began the Northern Satellite Monitoring Program in 1997, with the objective of tracking large‐scale vegetation variation in Canadian ecosystems and helping land managers to develop appropriate management practices in response to climate change. Under this program, a sequence of 10‐day composite Advanced Very High Resolution Radiometer (AVHRR)‐derived Normalized Difference Vegetation Index (NDVI) data from 1985 to 2007 was examined to study seasonal and inter‐annual relationships between vegetation and climate data over Canadian ecosystems using statistical and wavelet analysis. Statistical analysis showed that temperature was the principal driver for seasonal variability in greenness, explaining more than 70 percent of seasonal variation in vegetation for most Canadian ecozones. In comparison with temperature, the relationships between NDVI and precipitation were weaker but still significant. Maximum annual NDVI showed increasing trends in Canadian ecozones during the study period, although increasing rates were spatially heterogeneous. Wavelet analysis confirmed that inter‐annual variation in NDVI was different at two ecozones in Canada. NDVI variation in the Northern Arctic was significant at scales of 3–4 years from 1997 to 2001, which was associated with temperature and precipitation variation. Comparatively, NDVI variation in the Boreal Shield was significant at scales of 5–8 years from 1991 to 1999, but did not correspond with climate variation.     

Refilling process in the plasmasphere and its relation to magnetic activity

When geomagnetic activity is moderate, the geosynchronous orbit crosses the plasmasphere bulge region in which the variations of plasma density from day to day can therefore be detected by geosynchronous satellites. The plasma density was measured by the Relaxation Sounder onboard ESA's GEOS-2 satellite. Variations of plasma density reflect the combined effects of refilling of particles from the ionosphere and loss of plasma by convection. The saturation level of the electron density at the geo-synchronous orbit and the refilling rate under different conditions of geomagnetic activity have been obtained and are found to be 70.5 cm⁻³ and 7–25 cm⁻³ day⁻¹, respectively. In this paper the refilling morphology and the relationship between the refilling process and magnetic activity (Dst index) are analysed. The refilling rate or refilling time constant inferred from the data, either directly on fairly well-defined refilling events, or indirectly through a simple model, are found to compare reasonably well with the refilling time constant expected by theory. The observed correlation of refilling rate with Dst index is interpreted as resulting from the modification of the composition of the topside ionosphere occurring after intense storms.     

Diffused light and sunlight in relation to relief and settlement in high latitudes

The Mameluke or Slave Dynasty of Egypt. By Sir William Muir, K.C.S.I., LL.D., D.C.L., Ph.D. (Bologna). London : Smith, Elder, and Co., 1896.

Hausaland; or, Fifteen Hundred Miles through the Central Soudan. By Chas. Henry Robinson, M.A. London : Sampson Low and Co., 1896. Pp. 304.

Terre d'Espagne. Par René Bazin. Paris : Calmann Lévy, 1896. Pp. 336. Price 3 fr. 50 c.

The Gold Diggings of Cape Horn: A Study of Life in Tierra del Fuego and Patagonia. By John R. Spears. New York and London : G. P. Putnam's Sons, 1895. Pp. x + 319.

Parts of the Pacific. By A Peripatetic Parson. London : Swan Sonnenschein and Co., 1896. Pp. 388. Price 10s. 6d.

Folk og Natur i Finmarken. Af Hans Reusch. Kristiania : i Kommission hos T. O. Brögger, 1895. Pp. 176. Price 3 Kr.

National Geographic Monographs, prepared under the auspices of the National Geographic Society. New York, Cincinnati, Chicago : American Book Company, 1895. Vol. i., large 8vo, pp. 336. Price $1.50.

Elementary Physical Geography. By Ralph S. Tare, B.Sc., F.G.S.A. New York : Macmillan and Co., 1895. Pp. xxxii + 488; illus. 267 + plates 29. Price 7s. 6d. net.

Ice‐work, Present and Past. By T. G. Bonney, D.Sc., LL.D., F.R.S., etc., Professor of Geology, University College, London. London : Kegan Paul, Trench, Trübner and Co., Limited, 1896. 8vo, pp. 295. Price 5s.

Ethnology. In Two Parts. I.—Fundamental Ethnical Problems; II.—The Primary Ethnical Groups. By A. H. Keane, F.R.G.S. Cambridge : At the University Press, 1896. Pp. xxx + 442. Price 10s. 6d.

Bibliographie du Congo, 1880–1895. Catalogue méthodique de 3,800 Ouvrages, Brochures, Notices, et Cartes. Par A. J. Wauters. Bruxelles : Administration du Mouvement Géographique, 1895. Pp. 356.

Postal Directory of the Madras Circle, showing the Name of each Village in the, Madras Presidency and of the Post Town through which it is served. First edition. 3 vols. folio, pp. 1506. Madras, 1893 [not for sale].

Pacific Line Guide to South America, containing information for Travellers and Shippers to Ports on the East and West Coasts of South America. London : Simpkin, Marshall, and Co. ; Liverpool: Rockliff Brothers, 1895. Pp. 157. Price 2s. 6d. net.

Cocoa : All about it. By Historicus. London : Sampson Low, Marston, and Co., 1896. Pp. 99.     

Defining competences for future geography students in relation to low carbon societies

ABSTRACT

This paper presents the results of an analysis of the most important skills and competences that will be important in the coming years for future geographers involved in assessing and managing low-carbon societies. The analysed information was extracted from a questionnaire answered by professionals working in low-carbon management in three European countries (Finland, Poland and Catalonia, Spain). From the results, we have identified not only the most requisite abilities and skills, but also differences between countries on a European scale. Among the findings, we would highlight the general agreement that “soft skills”, as opposed to “hard skills”, are critical for future professionals addressing policies in relation to low carbon societies.     

High-latitude plasma densities and their relation to riometer absorption

A large number of D- and E-region electron density profiles from high latitudes have been analysed. These were derived from rocket-borne wave propagation experiments and—after careful screening—arranged according to riometer absorption. Statistical profiles for various degrees of absorption, including 0 dB, were established both for day and night. Furthermore, the height region predominantly contributing to the absorption has been identified. Finally a mean variation of the density of negative ions has been derived.     

Diatom-inferred salinity changes in relation to Holocene sea-level fluctuations in estuarine environments of Argentina

Espinosa, M.A., Hassan, G.S. & Isla, F.I., September 2012. Diatom-inferred salinity changes in relation to Holocene sea-level fluctuations in estuarine environments of Argentina. Alcheringa 36, 377–391. ISSN 0311-5518.

The analysis of diatoms from three sedimentary sequences in the Quequén Grande River basin (Buenos Aires province, Argentina) has allowed the reconstruction of local and regional palaeosalinity changes in relation to Holocene sea level fluctuations. An established diatom-based salinity transfer function is used in combination with autecological methods to reveal a maximum sea level between ca 7000 and 6000 ¹⁴C years BP. This marine influence was recorded in deposits exposed 2 km and 12 km upstream, but not 32 km from the mouth. The fossil diatom assemblages are characteristic of an estuarine lagoon with maximum inferred salinities of 15‰. When the Holocene transgression began to flood the former valley (ca 7000 ¹⁴C years BP), brackish lagoons evolved into estuarine settings in the lower valley, but shallow freshwater ponds with salinities <4‰ persisted at 32 km from the mouth.     

Tourist motivations in relation to a battlefield: a case study of Kinmen

ABSTRACT

To assess tourist motivations at the battlefield site on Kinmen Island of Taiwan, an empirical investigation was conducted. From a convenience sample, we collected 437 effective responses of respondents including domestic and international tourists with different cultural background in Kinmen. The structure of motivation was first examined via factor analysis. Then ANOVA analysis was applied to address the influence from demographic aspects such as gender, age, and nationality. Our results show that personal, spiritual, experience, physical, and emotional perspectives are five major sources of motivations. More importantly, age and nationality are confirmed to be two major dimensions to segment tourists in the context of battlefield tourism. Tourists with older age have higher motivations toward the battlefield site in comparison with young tourists. In addition, tourists with different cultural background based on different nationalities are significantly motivated by various motivational factors. The example of Kinmen contributes theoretically to a better understanding of the motivational attributes in a battlefield site, and how they represent a basis for increasing tourist perceptions. The motivational mechanisms and factors explored in this case can be incorporated into marketing strategies. Additionally, our results also provide a viable basis for the tourism authorities concerned to reevaluate the essence of its tourism industry in the context of battlefield resources and attractions.     

Validity of IRI electron density profiles in relation to vertical incidence absorption measurements

The observed discrepancies between A1 absorption meaurements and numerical estimation of the same using IRI electron density profiles are attributed to the assumption made in the Sen-Wyleer generalized magneto-ionic theory that the momentum transfer collision frequency of electrons with neutrals is proportional to the square of the electron thermal speed. Based on Budden's (1985) suggestion that, in the lower thermosphere and mesosphere, the momentum transfer collision frequency is proportional to the electron thermal speed, a generalized magneto-ionic theory has been outlined. The new theory brings experimental measurements of A1 absorption closer to the theoretical deductions based on IRI-90 electron density profiles.     

试析中苏关系破裂的原因

中苏关系破裂的原因是多方面的,主要有:中苏在意识形态领域发生分歧;以赫鲁晓夫为首的苏联大力推行大国沙文主义损害了中国的国家利益;以毛泽东为首的中共中央对马克思主义理解出现偏差并日趋"左"倾.中苏关系的这一段曲折历史为世界各国正确处理国际事务提供了前车之鉴,国际关系只有建立在和平共处五项原则的基础上,我们才能拥有和平有序的世界.