Latitudinal variations in the solar wind electron heat flux

Ulysses measurements of the solar wind electron heat flux as a function of heliographic latitude are presented. The latitudinal in the electron heat flux presented have been normalized by the radial gradient in the electron heat flux obtained during the in-ecliptic phase of the Ulysses mission (q_e R^–3.0). We find no significant variation in electron heat flux with latitude.     

Interplanetary shock waves generated by solar flares

Recent observational and theoretical studies of interplanetary shock waves associated with solar flares are reviewed. An attempt is made to outline the framework for the genesis, life and demise of these shocks. Thus, suggestions are made regarding their birth within the flare generation process, MHD wave propagation through the chromosphere and inner corona, and maturity to fully-developed coronal shock waves. Their subsequent propagation into the ambient interplanetary medium and disturbing effects within the solar wind are discussed within the context of theoretical and phenomenological models. The latter — based essentially on observations — are useful for a limited interpretation of shock geometric and kinematic characteristics. The former — upon which ultimate physical understanding depends — are used for clarification and classification of the shocks and their consequences within the solar wind. Classification of limiting cases of blast-produced shocks (as in an explosion) or longer lasting ejecta (or piston-driven shocks) will hopefully be combined with the study of the flare process itself.The theoretical approach, in spite of its contribution to clarification of various concepts, contains some fundamental limitations and requires further study. Numerical simulations, for example, depend upon a non-unique set of multi-parameter initial conditions at or near the Sun. Additionally, the subtle but important influence of magnetic fields upon energy transport processes within the solar wind has not been considered in the numerical simulation approach. Similarity solutions are limited to geometrical symmetries and have not exploited their potential beyond the special cases of the blast and the constant-velocity, piston-driven shock waves. These continuum fluid studies will probably require augmentation or even replacement by plasma kinetic theory in special situations when observations indicate the presence of anomalous transport processes. Presently, for example, efforts are directed toward identification of detailed shock structures (as in the case of Earth's bow shock) and of the disturbed solar wind (such as the piston).Further progress is expected with extensive in situ and remote monitoring of the solar wind over a wide range of heliographic radii, longitudes and latitudes.This paper is a revised and updated version of an invited review originally presented at the IUGG XV General Assembly, Moscow, U.S.S.R., 2–14 August 1971.     

Large-scale and solar-cycle variations of the solar wind

This paper summarizes space probe observations relevant to the determination of the large-scale, three-dimensional structure of the solar wind and its solar cycle variations. Observations between 0.6 and 5 AU reveal very little change in the average solar-wind velocity, but a pronounced decrease in the spread of velocities about the average. The velocity changes may be accompanied by a transfer of energy from the electrons to the protons. The mass flux falls off approximately as the inverse square of distance as expected for spherically symmetric flow. Measurements of the interplanetary magnetic field show that the spiral angle is well defined over this entire range of distances, but there is some evidence that the spiral may wind up more slowly with distance from the Sun than predicted by Parker's model. The variances or noise in the field and plasma have also been measured as a function of radial distance.During the rising portion of the solar-activity cycle, the solar-wind velocity showed a pronounced positive correlation with solar latitude over the range ±7°. Several other plasma parameters which have been found generally to correlate (or anticorrelate) with velocity also showed a latitude variation; these parameters include the density, percent helium, and azimuthal flow direction. The average polarity and the north-south component of the magnetic field depend on the solar hemisphere in which the measurements are made.Dependence on the phase of the solar-activity cycle can be found in the data on the number of high speed streams, the proton density, the percent helium, and the magnetic-field strength and polarity.     

Large scale circulation patterns of the stratosphere

On the basis of analyses of the geographical, vertical and annual distribution for the northern hemisphere temperatures, geopotential heights, and winds at stratospheric pressure levels the general circulation patterns of the stratosphere are presented. Special attention is given to the outstanding features of stratospheric midwinter warmings and their variations in time, space, and intensity. The effects of the quasi-biennial oscillation at stratospheric levels are described. Finally some aspects of the observational problems are discussed.     

Interaction of non-perpendicular/parallel solar wind shock waves with the earth's magnetosphere

The interaction of travelling interplanetary shock waves with the bow shock-magnetosphere system is considered. We consider the general case when the interplanetary magnetic field is oblique to the Sun-planetary axis, thus, the interplanetary shock is neither parallel nor perpendicular. We find that an ensemble of shocks are produced after the interaction for a representative range of shock Mach numbers. First, we find that the system S ₊ R _– CS _– S ₊ appears after the collision of travelling fast shock waves S ₊ (Mach number M = 2 to 7) with the bow shock. Here, S _– and R _– represent the slow shock wave and slow rarefaction wave, and C represents the contact surface. It is shown that in the presence of an interplanetary field that is inclined by 45° to the radial solar wind velocity vector, the waves R _– and S _– are weak waves and, to the first degree of approximation, the situation is similar to the previously studied normal perpendicular case. The configuration, R ₊ C _m S _– S ₊ or R ₊ C _m R _– S ₊ where C _m is the magnetopause, appears as the result of the fast shock wave's collision with the magnetopause. In this case the waves S _– and R _– are weak. The fast rarefaction wave reflected from the magnetosphere is developed similar to the case for the collision of a perpendicular shock. The shock wave intensity is varied for Mach numbers from 2 to 10. Thus, in the limits of the first approximation, the validity of the one-dimensional consideration of the nonstationary interaction of travelling interplanetary shock waves with the bow shock-magnetosphere system is proved. The appearance of the fast rarefaction wave, R ₄, decreasing the pressure on the magnetosphere of the Earth after the abrupt shock-like contraction, is proved. A possible geomagnetic effect during the global perturbation of the SSC or SI⁺ type is discussed.An invited paper presented at STIP Workshop on Shock Waves in the Solar Corona and Interplanetary Space, 15–19 June, 1980, Smolenice, Czechoslovakia.     

入射喷口宽度对环形射流激波聚焦起爆爆震的影响分析

为了研究射流入射喷口宽度对环形激波聚焦爆震起爆的影响,本文以氢气和空气混合物为例,对不同射流入射喷口宽度的环形激波聚焦爆震起爆过程进行了数值模拟,结果表明,当入射温度为一定值时,不同宽度的环形射流入射喷口对应着不同入射压力pin的临界值,当pin大于该临界值时,其形成的激波聚焦才能够形成高温、高压区域,从而起爆爆震波;随着入射喷口宽度的增加,射流的入射强度增大,其对应的临界入射压力随之减小。     

平流层飞艇飞行控制研究综述

综述了平流层飞艇控制研究的最新成果和发展动态,系统分析了反馈线性化控制、变结构控制、自适应控制、智能控制等方法的特点及其在飞艇控制系统设计中的研究应用现状。在总结已有研究成果的基础上,针对平流层飞艇的环境特性和应用特点,提出了需进一步研究的重难点问题,包括多物理场耦合与协调控制、上升段航迹优化与控制、异类执行机构复合控制等,并对今后的发展趋势进行了展望。     

Pioneer and Voyager observations of large-scale spatial and temporal variations in the solar wind

The Pioneer 10, Pioneer 11, and Voyager 2 spacecraft were launched in 1972, 1974, and 1977, respectively. While these three spacecraft are all at compartively low heliographic latitudes compared with Ulysses, their observation span almost two solar cycles, a range of heliocentric distances from 1 to 57 AU, and provide a unique insight into the long-term variability of the global structure of the solar wind. We examine the spatial and temporal variation of average solar wind parameters and fluxes. Our obsevations suggest that the global structure of the outer heliosphere during the declining phase of the solar cycle at heliographic latitudes up to 17.5°N was charaterized by two competing phenomena: 1) a large-scale increase of solar wind density, temperature, mass flux, dynamic pressure, kinetic energy flux, and thermal enery flux with heliographic latitude, similar to the large-scale latitudinal gradient of velocity seen in IPS observations, 2) a small-scale decrease in velocity and temperature, and increase in density near the heliospheric current sheet, which is associated with a band of low speed, low temperature, and high density solar wind similar to that observed in the inner heliosphere.     

Exploration of the solar corona by high resolution solar decametric observations

In this review, current state of knowledge of high resolution observations at decameter wavelengths of the quiet Sun, the slowly varying component (SVC), type I to V bursts and noise storms is summarized. These observations have been interpreted to yield important physical parameters of the solar corona and the dynamical processes around 2R from the photosphere where transition from closed to open field lines takes places and the solar wind builds up. The decametric noise bursts have been classified into (i) BF type bursts which show variation of intensity with frequency and time and (ii) decametric type III bursts. The angular sizes of noise storm sources taking into account refraction and scattering effects are discussed. An attempt has been made to give phenomenology of all the known varieties of decametric bursts in this review. Available polarization information of decametric continuum and bursts has been summarized. Recent simultaneous satellite and ground-based observations of decametric solar bursts show that their intensities are deeply modulated by scintillations in the Earth's ionosphere. Salient features of various models and theories of the metric and decametric noise storms proposed so far are examined and a more satisfactory model is suggested which explains the BF type bursts as well as conventional noise storm bursts at decametric wavelengths invoking induced scattering process for 1 t conversion. Some suggestions for further solar decametric studies from the ground-based and satellite-borne experiments have been made.     

Numerical study on influence of protrusion heights on Reynolds stress and viscous stress variations in turbulent vortical structures

Analysing the influence mechanism of the riblet protrusion height on turbulent drag components is more beneficial in organising the vortical structure over the riblet surface.Therefore,the Large Eddy Simulation(LES)is used to investigate the vortex structure over the rib-let surface with different protrusion heights.Then,the variations of Reynolds stress and viscous shear stress in a turbulent channel are analysed.As a result,the drag reduction rate increases from 3.4％when the riblets are completely submerged in the turbulent boundary layer to 7.9％when the protrusion height is 11.2.Further analysis shows that the protrusion height affects the streamwise vortices and the normal diffusivity of spanwise and normal vortices,thus driving the variation of Reynolds stress.Compared with the smooth surface,the vorticity strength and the number of streamwise vortices are weakened near the wall but increase in the logarithmic layer with increased protrusion height.Meanwhile,the normal diffusivity of spanwise vorticity decreases with the increase of protrusion height,and the normal diffusivity of normal vorticity is the smallest when the protrusion height is 11.2.Moreover,the protrusion height affects the velocity gradient of the riblet tip and riblet valley,thus driving the variation of viscous shear stress.With the increase of protrusion height,the velocity gradient of the riblet tip increases dramatically but decreases in the riblet valley.     

Japanese satellite program on the solar research for the coming solar maximum

The Institute of Space and Astronautical Science (ISAS) is developing a satellite dedicated to high-energy observations of solar flares. The Solar-A will be launched in August–September, 1991, from the Kagoshima Space Center on board a M3S-II vehicle. The instrument complement emphasizes hard X-ray and soft X-ray imaging, with both high resolution (2.4 arc sec pixel size) and full-Sun field of view. Solar-A contains instruments supplied in part by U.S. and U.K. experimenters. This paper describes the instrumentation and the tentative observing program.     

Japanese satellite program on the solar research for the coming solar maximum

The paper discusses the methods for measuring the linear polarization of gamma-rays with energies above 0.1 MeV. Special attention is given to Compton scattering and e ^–, e ⁺ pair production. The effects of the selection of gamma-events and multiple scattering in the converters on the derived azimuthal distribution are considered. The changes of measuring polarization with gamma-telescopes in a near future are considered.     

Air motions in the tropical stratosphere deduced from satellite tracking of horizontally floating balloons

Between June and November of 1970, 26 constant level balloons were released from Ascension Island (8 S) for flight at 30 and 50 mb. The balloons were positioned by the Interrogation, Recording and Location System (IRLS) aboard the Nimbus D satellite. In general, balloon positioning appeared to be accurate to within a few kilometers, although occasionally there was doubt as to whether the balloon position was to the right or left of the satellite subtrack. Eight of the flights at 50 mb and three of the flights at 30 mb were tracked for more than one month, and one 50 mb flight was tracked continuously for more than 5 months while making 7 circumnavigations of the Earth. From the satellite-determined 12-hourly balloon positions in the tropics, 223 smoothed 24-hour-average zonal and meridional winds were obtained at 30 mb and 693 such winds were obtained at 50 mb. Near the equator the balloons moved from east to west at a speed of about 23 ms^–1 at 50 mb and 28 ms^–1 at 30 mb, while undergoing a mean northward drift of approximately 0.1 ms^–1. The northward drift was a maximum in the Northern Hemisphere winter, suggesting a weak upward extension of the Hadley Cell to 50 mb. Superimposed on this drift were oscillations in meridional velocity of about 2-month period, with these oscillations also most pronounced in the Northern Hemisphere winter. Small (1–3 ms^–1) short-period fluctuations in meridional velocity were evident directly above the equator at 50 mb. These waves appear to move westward at speeds of 30–40 ms^–1 and to have a wavelength of about 90° longitude. They were responsible for transporting small amounts of westerly momentum into the winter hemisphere. Fluctuations in zonal velocity (Kelvin waves) were also delineated by flights near the equator. These waves appear to move eastward at speeds of 30–40 ms^–1 and to have a wavelength of 360° longitude. Some comparisons are made between these IRLS data and the data obtained from GHOST balloon flights at the same heights in early 1969.     

新型太阳能利用装置的研究

对目前太阳能的几种常见的应用领域及相关装置进行了分析和研究,并在此基础上,结合相关理论,设计了利用太阳能的新型装置,如:太阳能房、太阳能热发电装置、聚光式太阳能电池发电装置等,这些装置将为更好地利用太阳能开辟新的途径.太阳能作为一种新兴的可再生能源有着不可限量的发展前景.     

Observation of flare-generated shock waves by Helios-2 near the sun

We present the observation of three flare generated shock waves which were measured by Helios-2 at a radial distance from the Sun of 0.476 AU, 0.444 AU, and 0.297 AU. These results show that two of the shocks fulfill the classification scheme of F-events stated in the past while the third shock profile is that of a R-event being interpreted as a driven wave. Because of the close distance to the Sun a flare-association was possible. Only in one case there is some evidence for a piston in the downstream region of the shock. One of the shocks is characterized by a distinct hole in the frequency distribution of directional discontinuities in the downstream region.An invited paper presented at STIP Workshop on Shock Waves in the Solar Corona and Interplanetary Space, 15–19 June, 1980, Smolenice, Czechoslovakia.     

Detection of solar neutrons by ground-based neutron monitor

A review is presented of solar neutron observation by ground-based neutron monitors (NM), focusing on the five solar neutron events of 1980 June 7, 1980 June 21, 1980 November 6, 1982 November 26, and 1984 April 25 observed by the Tokyo NM. These events are analyzed by comparison with the time profiles of gamma-rays observed by the Gamma-Ray Spectrometer (GRS) on the Solar Maximum Mission (SMM) satellite and with the enhancements of counting rate observed at various NM stations in the solar neutron event of 1982 June 3.The energy range of solar neutrons observed by the NM is estimated in each event, based on some simple assumptions, using the gamma-ray data from the GRS and decay proton data from the ISEE-3 spacecraft. It is shown that these enhancements can be almost completely explained by the continuous emission of solar neutrons for several minutes at the flare. Finally, the effective detection and the newly found possibility to predict, in the short term, the occurrence time of a solar neutron event, and the plans for observation of solar neutrons by the ground-based NM stations are presented.     

青草沙,凌波仙子的惊鸿瞥

上海"十一五"期间投资规模最大的民生工程——长江口青草沙水源地主体工程于六月建成通水,受益总人口超过一千一百万人。青草沙水源地工程日供水规模七百一十九万立方米,总投资一百七十亿元人民币。