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Solar Wind Seven
Book reviews attributed to periodic changes due to the Sun’s rotation. At the first meeting of COSPAR, held in Nice, France, in January 1960, King-Hele presented a paper on the mathematical theory of satellite drag caused by a spherically symmetrical atmosphere. Chapter 4 discusses research in the 196Os, exploiting the techniques devised earlier. At the second COSPAR meeting King-Hele and Walker showed, for example, that, at 500 km altitude, the daytime density was 25 times greater in 1958 (at solar maximum) than in 1960, and that the daytime density was typically 5 times the nighttime value. The Smithsonian Astrophysical Observatory determined precise satellite orbits from observations made by Baker-Nunn cameras and Britain used the Hewitt camera. Ariel I, the first AngloU.S. satellite, was launched in April 1962. The density scale height was obtained from the observations of different satellites, superrotation further investigated and the Earth’s pear shape quantified as odd zonal harmonics in the gravity field. King-Hele’s interests in the history of science were developing. The next chapter deals with the next decade, resonant orbits, and sophisticated radar observations of orbiting satellites and debris. Refinements to orbital analysis are discussed, as is the launch in October 1971 of Britain’s Prospero satellite by the Black Arrow rocket from Woomcra. Chapter 6, the eighties. covers organisational rearrangements. the satellite laser ranger system at the RGO, Herstmonceux, and further refinements to earlier work. In Chapter 7, the new Optical Tracking Working Group is mentioned, set up when The Royal Society’s National Committees (for example for Space Research) were abolished. This fascinating book, superbly written from such a personal view, with many personal recollections. is a most worthwhile summary of King-Hele’s supremely worthwhile career in satellite orbit analysis-and other things. M. J. RYCKOF~ Cranfield Institute of Technology
Guide to the Sun, PHILLIPS K. J. H., 1992,386
Llniversity
pp. Cambridge Press, f19.95 hb, ISBN 0-521-39483-X.
This immediately appealing book describes (at the Scientific American level) how the Sun works. It is written-well written-for physicists, but it does not use any mathematics. Yet it has sufficient photographs and diagrams to bring the reader to an appreciation of both our present understanding and current research topics concerning the Sun. It is a ‘must’ for all who are keenly interested in solar-terrestrial physics. This broad-ranging work starts with a historical introduction to the subject of solar astronomy. Mentioning Sun \i OI>hip and mythology, it proceeds to observations-and deductions-by the ancient Greeks, to sunspots first observed by Galileo, to the eleven-year sunspot cycle discovered by Schwabe and investigated by Wolf and Carrington, to early aurora1 observations, solar spectroscopy (Newton, Fraunhofer, Lockyer), solar eclipses, solar photography, solar magnetic fields (Hale), solar-terrestrial connections (Gilbert, Halley, Maunder, Bartels), solar irradiance (Langley, Abbott), and solar observations across the electromagnetic spectrum from the ground and using rockets (Tousey). Chapter 2 considers the interior of the Sun-nuclear fusion, the neutrino problem, helioseismology and dynamo action. The photosphere, the solar ‘surface’, is the topic of Chapter 3 : this covers granulation and other fine structure,
937
e.g. faculae, differential rotation, the Sun’s diameter, the near-black-body spectrum and spectral lines (Doppler and Zeeman effects). Chapter 4 is on the chromosphere, where the temperature rises rapidly with increasing height in the solar atmosphere ; it considers spicules, ionised Ca II K lines at 393.4nm and the Ha line at 656.3 nm, the UV spectrum, and heating by the dissipation of MHD waves. The tenuous, outermost solar atmosphere. the corona at 2 x IO6 K, is the feature of Chapter 5. White light coronagraph (artificial eclipse) observations, ‘forbidden’ lines, X-ray emissions and ‘coronal holes’ (the absences of X-ray emission from certain parts of the Sun) make way for a discussion of coronal magnetic fields and prominences. Phenomena on the active Sun are informatively classified and explained in Chapter 6. Solar flares (their geometry, magnetic fields. X-ray emissions, radio and gamma ray spectra) are covered in 24 invaluable pages and coronal mass ejections in 5 pages. Magnetic field reconfiguration theories of solar activity are well explained in 19 pages. Chapter 7 is on the solar system, the solar wind and its interaction with the planets and comets. geomagnetic disturbances and the aurora, the Earth’s ionosphere, atmosphere, ozone depletion and climate. Here, as elsewhere throughout this book, readability is paramount; the scientists involved themselves feature as do their new theoretical ideas or observational results obtained by a wide variety of techniques. The Sun in comparison with other stars, its birth, life cycle and eventual death is the subject of Chapter 8. Stellar chromospheres, coronae and winds are considered. as are stellar activity and asteroseismology. Chapter 9 is on the practical matter of how solar energy may be harnessed for the benefit of mankind, via photosynthesis, thermal systems, photovoltaic cells or wind energy. Telescopes to observe the Sun and their special instrumentation, whether in the optical or radio regions of the spectrum, whether on the ground or in space, are reviewed in Chapter IO. One of the first images from the soft X-ray telescope on the Japanese Yohkoh satellite is shown on p. 350. Finally. there are two appendices. a glossary of 7 pages. a good bibliography (chapter by chapter). a list of references to the diagrammatic and tabular material, and a comprehensive subject index. With its eye-catching and dramatic cover, this is a very valuable new book for the readers of the Journul of‘ Atmosphwic tmd Tcrtzstriul Phjxic,s. M. J. RYCKO~T Cranfield Institute of Technology
Solar Wind Seven, E. MAKSCH and R. SCHWENN (eds), 1992,
71 I pp. Pergamon
Press, E95.00 hb, ISBN O-08-042049-4.
The seventh in the series, started in the 1960s. of conferences on the solar wind was held in September 1991 in Goslar, Germany. Being the third COSPAR colloquium on an important topic in space research, it attracted more than 200 scientists from 22 countries around the world. Here, 142 refereed papers are published to provide an up-to-the-minute account of research on the omnipresent solar wind which flows supersonically away from the Sun and permeates the heliosphere. The papers range from theoretical to modelling studies and to experimental observations. They are divided into five sections, the first of which (134 pp) is concerned with coronal heating and solar wind acceleration. W. I. Axford and J. F. McKenzie introduce the topic of the origin of high speed
938
Book reviews
solar wind streams emanating from ‘coronal holes’; they propose that the minor ions are heated by cyclotron interactions. Energy constraints on various acceleration and heating mechanisms involving divers plasma waves are considered by others. Observations of explosions on the Sun are interpreted by K. P. Dere in terms of bursty magnetic reconnection (‘microflares’). Clues to the heating mechanisms may be obtained from solar wind observations obtained from spacecraft near 1 A.U. ; these are discussed by M. Neugebauer. The large-scale structure of the interplanetary medium is the title of the second section of 188 pages. The structure is closely related to the geometry of the interplanetary magnetic field. Some early Ulysses spacecraft data on the solar wind plasma are reported, and complemented by results from various instruments aboard Pioneers 10 and 11, Voyagers 1 and 2, IMPS, Pioneer-Venus, Prognoz 6, and Helios I and 2. Interplanetary scintillations of distant discrete radio sources (at different frequencies) provide indirect information. High resolution observations of the photospheric magnetic field since 1976 are presented as maps for each solar rotation by J. T. Hoeksema. An important result for solar-terrestrial physicists is that the average inclination of the heliospheric current sheet at 1.5 solar radii above the photosphere is only 15’ at solar minimum, rising to 75” at solar maximum. The modulations of cosmic rays by the heliospheric magnetic field are considered by J. Kota.
Section 3 (96 pp.) is concerned with minor ions, energetic neutral atoms and cosmic rays in the heliosphere. P. Bochsler shows how minor ions can be used as tracers of physical processes. Ulysses spacecraft observations on helium, carbon, oxygen, silicon, magnesium and iron are reported, as are earlier ISEE results. The kinetic treatment of the solar wind plasma, dealing especially with waves and turbulence, is the topic of Section 4 (176 pp.). The waves range from Alfven fluctuations to magnetosonic waves, ion cyclotron waves in multi-component plasmas, whistler waves. and electrostatic waves near the electron cyclotron frequency. Ulysses wave observations of seven interplanetary shocks are reported. Some particlein-cell simulations are presented by P. C. Liewer et ul. Finally, Section 5 is primarily on observations of hehospheric dynamic phenomena (106 pp.). These range from coronal mass ejection events on the Sun, to interplanetary magnetic flux tubes and kilometric radio bursts (discussed by B. V. Jackson). There are many interesting papers here, of interest to many researchers. It is rather odd, however, that the papers are arranged by alphabetic order of the first author within each section, rather than by the logical order of the topic.
Cranfield
Institute
M. J. RYCROFT of Technology
Guide to the Sun, PHILLIPS K. J. H., 1992,386
Llniversity
pp. Cambridge Press, f19.95 hb, ISBN 0-521-39483-X.
This immediately appealing book describes (at the Scientific American level) how the Sun works. It is written-well written-for physicists, but it does not use any mathematics. Yet it has sufficient photographs and diagrams to bring the reader to an appreciation of both our present understanding and current research topics concerning the Sun. It is a ‘must’ for all who are keenly interested in solar-terrestrial physics. This broad-ranging work starts with a historical introduction to the subject of solar astronomy. Mentioning Sun \i OI>hip and mythology, it proceeds to observations-and deductions-by the ancient Greeks, to sunspots first observed by Galileo, to the eleven-year sunspot cycle discovered by Schwabe and investigated by Wolf and Carrington, to early aurora1 observations, solar spectroscopy (Newton, Fraunhofer, Lockyer), solar eclipses, solar photography, solar magnetic fields (Hale), solar-terrestrial connections (Gilbert, Halley, Maunder, Bartels), solar irradiance (Langley, Abbott), and solar observations across the electromagnetic spectrum from the ground and using rockets (Tousey). Chapter 2 considers the interior of the Sun-nuclear fusion, the neutrino problem, helioseismology and dynamo action. The photosphere, the solar ‘surface’, is the topic of Chapter 3 : this covers granulation and other fine structure,
937
e.g. faculae, differential rotation, the Sun’s diameter, the near-black-body spectrum and spectral lines (Doppler and Zeeman effects). Chapter 4 is on the chromosphere, where the temperature rises rapidly with increasing height in the solar atmosphere ; it considers spicules, ionised Ca II K lines at 393.4nm and the Ha line at 656.3 nm, the UV spectrum, and heating by the dissipation of MHD waves. The tenuous, outermost solar atmosphere. the corona at 2 x IO6 K, is the feature of Chapter 5. White light coronagraph (artificial eclipse) observations, ‘forbidden’ lines, X-ray emissions and ‘coronal holes’ (the absences of X-ray emission from certain parts of the Sun) make way for a discussion of coronal magnetic fields and prominences. Phenomena on the active Sun are informatively classified and explained in Chapter 6. Solar flares (their geometry, magnetic fields. X-ray emissions, radio and gamma ray spectra) are covered in 24 invaluable pages and coronal mass ejections in 5 pages. Magnetic field reconfiguration theories of solar activity are well explained in 19 pages. Chapter 7 is on the solar system, the solar wind and its interaction with the planets and comets. geomagnetic disturbances and the aurora, the Earth’s ionosphere, atmosphere, ozone depletion and climate. Here, as elsewhere throughout this book, readability is paramount; the scientists involved themselves feature as do their new theoretical ideas or observational results obtained by a wide variety of techniques. The Sun in comparison with other stars, its birth, life cycle and eventual death is the subject of Chapter 8. Stellar chromospheres, coronae and winds are considered. as are stellar activity and asteroseismology. Chapter 9 is on the practical matter of how solar energy may be harnessed for the benefit of mankind, via photosynthesis, thermal systems, photovoltaic cells or wind energy. Telescopes to observe the Sun and their special instrumentation, whether in the optical or radio regions of the spectrum, whether on the ground or in space, are reviewed in Chapter IO. One of the first images from the soft X-ray telescope on the Japanese Yohkoh satellite is shown on p. 350. Finally. there are two appendices. a glossary of 7 pages. a good bibliography (chapter by chapter). a list of references to the diagrammatic and tabular material, and a comprehensive subject index. With its eye-catching and dramatic cover, this is a very valuable new book for the readers of the Journul of‘ Atmosphwic tmd Tcrtzstriul Phjxic,s. M. J. RYCKO~T Cranfield Institute of Technology
Solar Wind Seven, E. MAKSCH and R. SCHWENN (eds), 1992,
71 I pp. Pergamon
Press, E95.00 hb, ISBN O-08-042049-4.
The seventh in the series, started in the 1960s. of conferences on the solar wind was held in September 1991 in Goslar, Germany. Being the third COSPAR colloquium on an important topic in space research, it attracted more than 200 scientists from 22 countries around the world. Here, 142 refereed papers are published to provide an up-to-the-minute account of research on the omnipresent solar wind which flows supersonically away from the Sun and permeates the heliosphere. The papers range from theoretical to modelling studies and to experimental observations. They are divided into five sections, the first of which (134 pp) is concerned with coronal heating and solar wind acceleration. W. I. Axford and J. F. McKenzie introduce the topic of the origin of high speed
938
Book reviews
solar wind streams emanating from ‘coronal holes’; they propose that the minor ions are heated by cyclotron interactions. Energy constraints on various acceleration and heating mechanisms involving divers plasma waves are considered by others. Observations of explosions on the Sun are interpreted by K. P. Dere in terms of bursty magnetic reconnection (‘microflares’). Clues to the heating mechanisms may be obtained from solar wind observations obtained from spacecraft near 1 A.U. ; these are discussed by M. Neugebauer. The large-scale structure of the interplanetary medium is the title of the second section of 188 pages. The structure is closely related to the geometry of the interplanetary magnetic field. Some early Ulysses spacecraft data on the solar wind plasma are reported, and complemented by results from various instruments aboard Pioneers 10 and 11, Voyagers 1 and 2, IMPS, Pioneer-Venus, Prognoz 6, and Helios I and 2. Interplanetary scintillations of distant discrete radio sources (at different frequencies) provide indirect information. High resolution observations of the photospheric magnetic field since 1976 are presented as maps for each solar rotation by J. T. Hoeksema. An important result for solar-terrestrial physicists is that the average inclination of the heliospheric current sheet at 1.5 solar radii above the photosphere is only 15’ at solar minimum, rising to 75” at solar maximum. The modulations of cosmic rays by the heliospheric magnetic field are considered by J. Kota.
Section 3 (96 pp.) is concerned with minor ions, energetic neutral atoms and cosmic rays in the heliosphere. P. Bochsler shows how minor ions can be used as tracers of physical processes. Ulysses spacecraft observations on helium, carbon, oxygen, silicon, magnesium and iron are reported, as are earlier ISEE results. The kinetic treatment of the solar wind plasma, dealing especially with waves and turbulence, is the topic of Section 4 (176 pp.). The waves range from Alfven fluctuations to magnetosonic waves, ion cyclotron waves in multi-component plasmas, whistler waves. and electrostatic waves near the electron cyclotron frequency. Ulysses wave observations of seven interplanetary shocks are reported. Some particlein-cell simulations are presented by P. C. Liewer et ul. Finally, Section 5 is primarily on observations of hehospheric dynamic phenomena (106 pp.). These range from coronal mass ejection events on the Sun, to interplanetary magnetic flux tubes and kilometric radio bursts (discussed by B. V. Jackson). There are many interesting papers here, of interest to many researchers. It is rather odd, however, that the papers are arranged by alphabetic order of the first author within each section, rather than by the logical order of the topic.
Cranfield
Institute
M. J. RYCROFT of Technology