1988 Vol. 8, No. 4

Display Method:
The Power Spectrum of Alfvenic Fluctuations Propagating in Unisotropic Solar Wind
Tu Chuan-yi
1988, 8(4): 241-252. doi: 10.11728/cjss1988.04.241
Abstract(1470) PDF 831KB(855)
Abstract:
The power spectrum equation proposed by Tu et al.for Alfvenic fluctuations propogating in an isotropic plasma is extended to the case of unisotropic medium.
X-ray Eclipse Transitions in Her X-1/HZ Her Binary and the Atmospheric Structure of HZ Her
Mi Guo-zhu, Shen Jing-ying
1988, 8(4): 253-260. doi: 10.11728/cjss1988.04.253
Abstract(1553) PDF 633KB(921)
Abstract:
In close binary system Her X-I/HZ Her,the gradual occultations of the X-ray pulsar Her X-1 by its companion HZ Her offer a direct observational evidence of the atmospheric structure of HZ Her.The transitions in two observations have been fitted and studied.We find that there exists a chromosphere layer with temperature about 8×104K due to X-ray heating at the bottom of HZ Her atmosphere facing the X-ray source.This conclusion is compared with previous theoretical models of HZ Her atmospheric structure.It agrees roughly with the models.Some disagreements are discussed briefly.
The Structure Characteristics of Simple Strong Magnetic Cloud
Zhang Gong-liang
1988, 8(4): 261-274. doi: 10.11728/cjss1988.04.261
Abstract:
MHD characteristics of interplanetary magnetic clouds has been studied for the simple case without large corotating stream interactions.The present discussions involve two strong clouds,the Dcember 19,1980,and March 19,1980 events moving in a high and a low speed solar wind streams respectively.The simple strong clouds are characterized by a main structure of low density and temperature but high magnetic field,the field vector of which rotates with a monotonically changing inclination 6 to the ecliptic plane.The main structure is proceeded by a turbulent high density and temperature structure,and followed by another less dense density enhancement.Large gradients of magnetic pressure Pm are observed at both the front and rear boundaries of the cloud.Inside the main structure of cloud,the Alfvenic speed Ca and ratios of the magnetic pressure to both the kinetic energy density and thermal pressure,μk and μp respectively are at least one order of magnitude higher than that in the background stream.Such a structure would help the MHD disturbances behind the cloud to propagate quickly across the cloud,and concntrate at the front boundary.It is suggestive that the magnetic gradient force due to expanding strong magnetic cloud as well as the dissipation of MHD waves in the high density structure could accelerate and heat the solar wind ahead of the cloud,build up the observed steep front in the speed profile and generate a forward shock.Also,there are indications that such expanding strong magnetic structure would be able to decelerate the solar wind from behind,and result in a double saw-teeth like speed profile similar to that observed in the outer,heliosphere.The structures of simple strong magnetic cloud could be compared with the structures observed successively in a typical coronal mass ejection event,i.e.a bright high density outer loop driven by a dark cavity with low density,presumably high magnetic field,inside which is an inner prominence core.In addition,the geomagnetic disturbances and cosmic ray decreases caused by the clouds" are briefly discussed in association with the Kp category of geomagnetic storms.
Axisymmetric Magnetostatic Equilibria I. Method of Infinitesimal Transformations
Hu You-qiu
1988, 8(4): 275-284. doi: 10.11728/cjss1988.04.275
Abstract(1563) PDF 700KB(837)
Abstract:
Axisymmetric magnetostatic equilibria have been widely applied to discribing stellar atmospheric structures of various scales.The so-called magnetic flux function may be introduced for such equilibria to represent the magnetic field,and it satisfies a nonlinear,elliptic equation with variable coefficients.Analytic solutions have been given only for certain spe-cialications of this equation so far,whereas in more complicated cases,especially nonlinear cases,no effective approach is found for analytic treatment.This paper uses the so-called method of infinitesimal transformations to derive similarity solutions of the nonlinear elliptic equation with variable coefficients,mentioned above,and presents some general results.The concrete forms of the solutions and their application to the solar atmosphere is relegated to the subsequent papers of this series.
Propagation and Evolution of an Acoustic Gravity Wave in a Region of Wind Shear
Yi Fan, Li Jun, Liang Bai-xian
1988, 8(4): 285-292. doi: 10.11728/cjss1988.04.285
Abstract(1579) PDF 658KB(976)
Abstract:
By using the fundamental equations describing the evolution of an acoustic gravity wave (AGW) packet in an ambient wind,the variation characteristics of AGW’s essential parameters in a region of wind shear are studied.It is shown that the variations of wavelength,phase velocity and propagation direction depend on the vertical structure of the wind and also on the direction of the wave with respect to the wind.The variation manner of AGW kinetic energy is related to the variation in the spatial scale of AGW.For the upgoing gravity branch,an increase of kinetic energy of the wave packet is accompanied by an increase of the wavelength,while a decrease of the kinetic energy is accompanied by a decrease of the wavelength.For the upgoing acoustic branch,the situation is just opposite.It is also discussed that an AGW wavetrain propagates in the region of wind shear.It is shown that an increase of AGW energy density is accompanied by a decrease of intrinsic frequency,while a decrease of AGW energy density is accompanied by an increase of intrinsic frequency.
Field-Aligned Current in the Magnetotail Lobe
Wu Ji-ping, Lin Jin-yun
1988, 8(4): 293-301. doi: 10.11728/cjss1988.04.293
Abstract(1546) PDF 675KB(888)
Abstract:
It is found that the bursts of energetic particle (electron: 75 keV≤Ee≤1300 keV,proton: 170 keV≤Ep<400 keV) and east-west magnetic field perturbations are sometimes observed simultaneously by ISEE-2 satellite in the magnetotail lobe far from the plasma sheet,which shows that there are field-aligned currents in the magnetotail lobe.The integral densities of the current sheet range from 3.3 to 21 mA/m.These values are comparable to previous observations of field-aligned current made by Frank et al.on the plasma sheet boun-dary of the magnetotail.The current sheets always appear in pairs and their integral densities have a good correlation with AE index.Differing from the other regions,eastwest mag-netic field perturbations are sometimes accompanied by south-north ones.The fact can be explained through moving linear current model or heterogeneous density model of current sheet.
Effects of Enhanced Auroral Disturbance on Mid-and Low Latitude Ionosphere
Gu Shi-fen, Song Li
1988, 8(4): 302-306. doi: 10.11728/cjss1988.04.302
Abstract(1582) PDF 457KB(955)
Abstract:
The behaviour of f0F2 from five stations located at mid-and low latitudes around 120°E during enhanced auroral disturbances is examined in this paper.The data used are classified into two groups,one is for the years of 1966 to 1970 under the conditions of AE larger than 1400,the others is from 1969 for AE larger than 1000.The results show some features different from those obtained on the chain of Indian stations for AE>1000.Instead of an increase,f0F2 on 120°E stations decreased in general to some extent,f0F2 of Manzhouli,being at higher latitude,decreased more markedly than that of lower latitude station like Beijing.In addition,this study also showed different behaviours of the after-effect of auroral disturbances for stations of different latitudes.The f0F2 at low latitude stations such as Wuchang,Guangzhou and Hainan exhibits an increase in the morning immediatly after the disturbance,meanahile,Manzhouli’s f0F2 is still decreasing.It is considered that at low latitude zone the f0F2 is affected mainly by changes of the equatorial fountain effect.At mid-latitude zone,however,it is influenced mainly by a global disturbed electric field during enhanced auroral disturbances,this is a manifestation of the latitudinal transfering coupling of electric field.Of course,perturbations of mid-and low latitude neutral atmosphere due to direct energy input into the auroral neutral atmosphere also contribute to the phenomena observed.
Several Problems on the Designing of the Millisecond Order Radio Receiver in Early 1980’s in Beijing Observatory
Zheng Le-ping, Liu Yu-ying
1988, 8(4): 307-315. doi: 10.11728/cjss1988.04.307
Abstract(1467) PDF 728KB(955)
Abstract:
The doubt is presented for the designing of early radio receiver at millisecond order in Beijing Observatory in this paper.Because of the mistakes in the design,we think that some artificial interferences were led into observations and the results are not the real situation.Moreover,above design causes the UFFS data of solar microwave burst on May 16,1981 no valid.