Simultaneous ground-based observations of the plasmapause and the F-region mid-latitude trough

The plasmapause and the mid-latitude ionospheric trough have been observed simultaneously from two Antarctic stations, Halley and Faraday, during five winter nights covering a range of geomagnetic disturbance conditions. The equatorial radius of the plasmapause was measured using whistlers recorded at Halley, whilst the poleward edge of the trough was located from ionospheric soundings at one or other of the stations.Before midnight the trough was well poleward of the plasmapause (by 1–2 L) when first observed (typically at ~21 LT), but then moved rapidly equatorwards. After local magnetic midnight the two features were roughly coincident, and in general moved slowly to lower L-shells with increasing local time. At no time were there simultaneous and identical movements of the two features, suggesting a lack of coupling between them. Agreement of the observations with statistical studies and models was fair, given the considerable variability among the five cases studied. For the geomagnetically quieter nights the trough data fit the Spiro model predictions, whereas in the most disturbed case, agreement is better with the Quegan et al. model. The latter model predicts a difference in L between the two features which would fit the data better if shifted 1–2 h later in local time.     

Calculations and ground-based observations of pulsed proton events in the dayside aurora

A procedure is established to evaluate the Balmer excitation rates of Hα and Hβ to produce the corresponding volume emission rates versus height, using semi-empirical range relations of protons in air. The calculations are carried out with identified ion-energy particle spectra of the dayside aurora obtained by low altitude satellites. The calculated emission intensities of Hα and Hβ indicate that they are indeed observable by ground-based optical detection. Measurements of the dayside aurora from Nordlysstasjonen in Adventdalen, Svalbard, are discussed in relation to these calculations. Periodic bursts of auroral Hα and Hβ emissions are observed in the dayside aurora by ground-based photometers and spectrometers. The mean period between proton events is found to be 10 min on average. Furthermore, it is found that when the time between successive bursts decreases, the emission ratio of Hα and Hβ fluctuates indicating a step-like behaviour in the primary initial proton energy.     

A comparison of PMSE and other ground-based observations during the NLC-91 campaign

During the period July–August 1991, observations were made of Polar Mesospheric Summer Echoes (PMSE) at 46.9 MHz and 224 MHz by the CUPRI and EISCAT radars, respectively, at two sites in northern Scandinavia. Those observations are compared here with observations of noctilucent clouds, energetic particle precipitation and magnetic disturbances. The appearance and morphology of PMSE are found to be closely correlated at the two frequencies and the two sites, 200 km apart. No correlation is found between PMSE and noctilucent clouds or magnetic disturbance. No correlation is found between energetic particle precipitation and the appearance of PMSE at 46.9 MHz for the whole time period. At 224 MHz, there is no evidence for a correlation before the beginning of August and only one event suggesting a possible correlation after the beginning of August. A minimum in occurrence frequency for PMSE is found between 16 and 21 UT (17–22 LST) which may be related to an expected minimum in background wind strength in that time interval.     

Lidar observations of atmospheric aerosols following the 1980 eruption Of Mt. St. Helens. Part I

A significant increase and subsequent variations of stratospheric aerosols caused by the eruption of Mt.St. Helens on 18 May 1980 have been observed using a Yag lidar at a wavelength of 1.06 μm for a period of one year at Fukuoka, Japan. The time variation of aerosols is compared with numerical results of two-dimensional model calculations, which show longer decay times, especially for column concentrations of aerosols.In the upper layer, transported by the easterly wind during summer, the effective vertical diffusion is quite small and this is explained,at least partly, by the influence of vertical shear of the easterly wind, which balances vertical eddy diffusion.Finally, it is suggested that the settling of giant particles might increase the precipitation near the Baiu front over Japan for July and August.     

Ground-based optical observations of daytime auroral emissions from Antarctica

First results obtained from ground-based observations on daytime amoral emission intensities from the Indian station, Maitri, in Antarctica, are presented and discussed. These results show striking increases in intensities in all the emissions (viz. low- and high-energy electron-induced and proton-induced emissions), during noon hours in a latitudinal region near the plasmapause and far from the conventional cusp zone. Wave-like disturbances are seen on moderately disturbed days in proton-induced emissions. Plausible causes for such enhancements and disturbances are discussed.     

Simultaneous ground-based observations of polar cap arcs and spacecraft measurements of particle precipitation

In order to investigate the particles which produce the polar cap aurora at the Vostok station in Antarctica, charged particle data obtained by the DMSP satellites for some days in a period from April to August 1985 were surveyed. Due to the satellite orbit the local time range in which the data were available was the morning sector. For all the events when sun-aligned arcs were observed on the ground the simultaneous DMSP measurements on almost the same field line showed an increased integral number flux J. > 10⁸ (cm⁸/s/sr)⁻¹ of the precipitating electrons with energy E_e > 200 eV. The electron spectra with double peaks are typical of intense electron precipitation in the polar cap arcs. The most noticeable feature of ion spectra in the polar cap arcs is the prominent minimum in ion flux in the energy range 0.1 < E_i < 1 keV in contrast with the oval precipitation ; this feature gives the possibility to separate the polar arcs from the aurora in the oval. In some events the satellite crossed the system of two widely separated arcs ; one of them was a sun-aligned arc whereas the other was circular at constant latitude according to the Vostok data. The analysis of the DMSP electron and ion precipitation data has shown that in these events the latitude-oriented arcs are located in the polar cap and not in the auroral oval.     

New Archaeocyatha from the Early Cambrian of the Mt. Wright area,New South Wales

An archaeocyathan fauna from a single limestone lens in the upper Cymbric Vale Formation at Mt. Wright shows species in common with the historic Ajax Mine fauna of the Flinders Ranges, South Australia. The Cymbric Vale fauna is considered equivalent to the lower Sanashtykgol ‘horizon’ of the Altay Sayan fold belt of Siberia.

New taxa described are the genera Hyptocyathus (Inessocyathacea, Hyptocyathidae fam. nov.), Aporosocyathus (Annulocyathidae), Wrighticyathus (Sigmocyathacea, Wrighticyathidae fam. nov.), Flexicyathus (Porocoscinidae) and Bractocyathus (Polycoscinidae), and the species Erugatocyathus cymbricensis and Veronicacyathus concavus.     

A Village at the Foot of Mt.Meli

ＡＶｉｌｌａｇｅａｔｔｈｅＦｏｏｔｏｆＭｔ．ＭｅｌｉＺＨＯＵＺＨＥＮＧＳｋｉｒｔｅｄｂｙｔｈｅＬａｎ－ｃａｎｇｊｉａｎｇａｎｄＮｕ－ｊｉａｎｇｒｉｖ－ｅｒｓ,ＭｅｌｉＭｏｕｎｔａｉｎｓｔａｎｄｓｍａ－ｊｅｓｔｉｃａｌｌｙａｔｔｈｅｂｏｒｄｅｒｂｅｔｗ...     

Current density models of the eastward electrojet derived from ground-based magnetic field and radar measurements

Correlated studies of the eastward auroral electrojet using EISCAT radar data and groundbased magnetic field observations from a meridional chain of five stations have been performed during the years 1987 and 1988. Three different models of current distributions—the line-type, the current sheet and the parabolic model—have been tested for their applicability in estimating the current density of the electrojet. The model employing a parabolic cross-section of the current density provides the best results, both from the magnetic profile and from the comparison of magnetic field and radar current density estimates. Current estimates from magnetic field observations are systematically 15% higher than those from EISCAT readings. This discrepancy has been attributed to the induction effect.     

Mesospheric temperatures and the OH layer height as derived from ground-based lidar and OH1 spectrometry

Night-time mesospheric temperatures were simultaneously determined from the Doppler broadening of the D₂ resonance line of atmospheric sodium excited by a laser and from the rotational distribution of the P₁(1), P₁(3) and P₁(4) lines of the OH(3,1) band by an i.r. spectrometer. Both instruments were located at the Andøya Rocket Range (69°N, 16°E). The mesospheric temperature gradient permits determination of the altitude of the OH¹ emitting layer from a comparison of the equivalent layer temperatures calculated from the height-resolved Na Doppler temperatures with the observed OH¹ rotational temperatures. The altitude of the OH¹ layer maximum is determined with an accuracy of ±4 km. For 3 nights in January 1986 the OH¹ emission layer is found near an altitude of 86 km.     

《醒世姻缘传》与泰山香社

托名“西周生”所著的《醒世姻缘传》是我国著名的古典文学作品,它是由作者根据社会现实生活创作完成的社会世情小说。作者借助一个冤冤相报的两世姻缘故事,意在如实反映明末清初的社会现实生活。在某种程度上,《醒世姻缘传》可以称为明末     

Radar and optical observations of mesospheric wave activity during the lunar eclipse of 6 July 1982

Simultaneous measurements were made using a 2.66 MHz interferometer radar, infrared photometers, and imaging systems during the total lunar eclipse of 6 July 1982. The radar data showed that a series of six discrete scatterers passed overhead at 103 km with an average spacing of 54 min, and two passed overhead at 88 km, also 54 min apart. The 88 km events were approximately 27 min out of phase with those at 103 km. One of the 88 km events was examined in detail; the radar returns appeared to come from a single scatterer or a few clustered scatterers, with a velocity of 135 m s⁻¹ almost due south, at 6° below the horizontal. The speed and period give a horizontal wavelength of 440 km, and the phase shift between 88 and 103 km activity suggests a 30 km vertical wavelength, in agreement with values for typical medium-scale traveling ionospheric disturbances (TIDs). Infrared images were made in the near infrared, and photometric measurements were made on and off the 8−3 band of OH. These observations, made from one site near the radar and a second site 575 km south, showed wavelike structures appearing first over the radar, then further south until they filled most of the sky. The speed of development of the infrared structure pattern in the sky is consistent with the 135 m s⁻¹ southward wave speed observed by the radar, but the structures themselves appeared in place, then drifted slowly northward at 10 m s⁻¹. The photographically determined wavelengths were 30–60 km, considerably shorter than the 440 km determined with the radar.     

泰山民间的"四仙"信仰

泰山周边民众在信奉佛教、道教大仙大神的同时,对狐、黄、猬、柳四仙信奉甚笃。这些动物在百姓的心目中都具有超自然的神力,能与神鬼相通,能给百姓禳祸降福,生财免灾。这种敬奉和信仰,起于汉唐,明清以降,尤多繁盛,直至民国年问,风俗仍浓。     

Recent techniques of observations and results from the magnetopause regions

The problems encountered in making measurements in the magnetopause regions are caused mainly by the variability of the phenomena and the space/time ambiguity of most satellite observations. The physical quantities of interest for magnetopause studies are listed, together with the range of values observed. As an example of a satellite equipped for magnetopause observations the HEOS-2 payload is described. Data mainly from this and from the OGO-5 spacecraft are used to bring out characteristic features of the magnetopause and show how the experimental problems are attacked.     

A comparison of low- and mid-latitude D region electron densities derived from ground-based radio data

Electron density profiles, 70–110 km, for almost identical solar zenith angles over Central Europe and over Ahmedabad (India) are compared, avoiding seasonal ‘anomalies’. Low- and mid-latitude profiles agree very well in their structural features, the maximum deviation in magnitude being by a factor of 2 (around 90 km).     

泰山"石敢当"信仰的两处文物遗存

民俗学者大多认为,石敢当信仰源于古代的泰山灵石崇拜.但泰山地区现存的古迹文物中,却极少有反映石敢当信仰的内容.近年笔者在泰山周边作考察时,新发现了两处关于石敢当信仰的文物遗存,可为研究这一民俗现象提供新的史证.……     

Ionospheric and atmospheric disturbances around Japan caused by the eruption of Mount Pinatubo on 15 June 1991

The disturbances observed by the Japanese ionospheric observation network following the explosions of Mount Pinatubo on 15 June 1991, are presented. Remarkable ionospheric fluctuations with periods of about 20 min appeared in the records of HF Doppler and total electron content (TEC) data. Traveling wave fronts of ionospheric disturbances scaled from these data give a northward horizontal velocity of 290 m/s. The surface pressure fluctuations due to the passage of atmospheric waves were confirmed by the microbarograph chain data in Japan. There existed three kinds of northward traveling pressure fluctuations; short-period (2–5 min) fluctuations with a horizontal velocity of 290 m/s, long-period (8–10 min) fluctuations with 300 m/s, and 17-min fluctuations with 281 m/s. It is concluded that the ionospheric and surface pressure waves were caused by the eruption of Mount Pinatubo.