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Chapter 10 IONOSPHERICRADIO WAVE PROPAGATION Section 10.1 S
Chapter 10 IONOSPHERICRADIO WAVE PROPAGATION Section 10.1 S. Basu, J. Buchau, F.J. Rich and E.J. Weber Section 10.2 E.C. Field, J.L. Heckscher, P.A. Kossey, and E.A. Lewis Section 10.3 B.S. Dandekar Section 10.4 L.F. McNamara Section 10.5 E.W. Cliver Section 10.6 G.H. Millman Section 10.7 J. Aarons and S. Basu Section 10.8 J.A. Klobuchar Section 10.9 J.A. Klobuchar Section 10.10 S. Basu, M.F. Mendillo The series of reviews presented is an attempt to introduce in HF communications is leading to a rejuvenation of the ionospheric radio wave propagation of interest to system global ionosonde network. users. Although the attempt is made to summarize the field, the individuals writing each section have oriented the work 10.1.1.1 Ionogram. Ionospheric sounders or ionosondes in the direction judged to be most important. are, in principle, HF radars that record the time of flight or We cover areas such as HF and VLF propagation where travel of a transmitted HF signal as a measure of its ionos- the ionosphere is essentially a "black box", that is, a vital pheric reflection height. By sweeping in frequency, typically part of the system. We also cover areas where the ionosphere from 0.5 to 20 MHz, an ionosonde obtains a meas- is essentially a nuisance, such as the scintillations of trans- urement of the ionospheric reflection height as a function ionospheric radio signals. of frequency. A recording of this reflection height meas- Finally, we have included a summary of the main fea- urement as a function of frequency is called an ionogram. -
Downloaded 09/27/21 06:58 AM UTC 3328 JOURNAL of the ATMOSPHERIC SCIENCES VOLUME 76 Y 2
NOVEMBER 2019 S C H L U T O W 3327 Modulational Stability of Nonlinear Saturated Gravity Waves MARK SCHLUTOW Institut fur€ Mathematik, Freie Universitat€ Berlin, Berlin, Germany (Manuscript received 15 March 2019, in final form 13 July 2019) ABSTRACT Stationary gravity waves, such as mountain lee waves, are effectively described by Grimshaw’s dissipative modulation equations even in high altitudes where they become nonlinear due to their large amplitudes. In this theoretical study, a wave-Reynolds number is introduced to characterize general solutions to these modulation equations. This nondimensional number relates the vertical linear group velocity with wave- number, pressure scale height, and kinematic molecular/eddy viscosity. It is demonstrated by analytic and numerical methods that Lindzen-type waves in the saturation region, that is, where the wave-Reynolds number is of order unity, destabilize by transient perturbations. It is proposed that this mechanism may be a generator for secondary waves due to direct wave–mean-flow interaction. By assumption, the primary waves are exactly such that altitudinal amplitude growth and viscous damping are balanced and by that the am- plitude is maximized. Implications of these results on the relation between mean-flow acceleration and wave breaking heights are discussed. 1. Introduction dynamic instabilities that act on the small scale comparable to the wavelength. For instance, Klostermeyer (1991) Atmospheric gravity waves generated in the lee of showed that all inviscid nonlinear Boussinesq waves are mountains extend over scales across which the back- prone to parametric instabilities. The waves do not im- ground may change significantly. The wave field can mediately disappear by the small-scale instabilities, rather persist throughout the layers from the troposphere to the perturbations grow comparably slowly such that the the deep atmosphere, the mesosphere and beyond waves persist in their overall structure over several more (Fritts et al. -
Variability of Martian Turbopause Altitudes M
Variability of Martian turbopause altitudes M. Slipski1, B. M. Jakosky2, M. Benna3,4, M. Elrod3,4, P. Mahaffy3, D. Kass5, S. Stone6, R. Yelle6 Marek Slipski; [email protected] 1Laboratory for Atmospheric and Space Physics, Department of Astrophysical and Planetary Sciences, University of Colorado Boulder, Boulder, CO, USA 2Laboratory for Atmospheric and Space Physics, Department of Geological Sciences, University of Colorado Boulder, Boulder, CO, USA 3NASA Goddard Space Flight Center, Greenbelt, MD, USA 4CRESST, University of Maryland, College Park, Maryland,USA This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1029/2018JE005704 c 2018 American Geophysical Union. All Rights Reserved. Abstract. The turbopause and homopause represent the transition from strong turbulence and mixing in the middle atmosphere to a molecular-diffusion dominated region in the upper atmosphere. We use neutral densities mea- sured by the Neutral Gas and Ion Mass Spectrometer (NGIMS) on the Mars Atmospheric and Volatile EvolutioN (MAVEN) spacecraft from February 2015 to October 2016 to investigate the temperature structure and fluctuations of the Martian upper atmosphere. We compare those with temperature mea- surements of the lower atmosphere from the Mars Reconnaissance Orbiter's (MRO) Mars Climate Sounder (MCS). At the lowest MAVEN altitudes we often observe a statically stable region where waves propagate freely. In con- trast, regions from about 20 km up to at least 70 km are reduced in stabil- ity where waves are expected to dissipate readily due to breaking/saturation. -
DEVELOPMENTS in UPPER ATMOSPHERIC SCIENCE The
DEVELOPMENTS IN UPPER ATMOSPHERIC SCIENCE DURING THE IQSY BY FRANCIS S. JOHNSON SOUTHWEST CENTER FOR ADVANCED STUDIES, DALLAS, TEXAS During the IQSY, there were of course many advances in the area of upper atmo- spheric science, and it would take a great deal of time and space to describe them all adequately. It is therefore necessary to arbitrarily select just a few of the advances that were, in my view, among the more important. Neutral Upper Atmosphere.-The vertical structure of the atmosphere is in large degree controlled by its temperature distribution, and the largest variations in temperature occur above 200-km altitude. This is illustrated in Figure 1, which shows a typical temperature distribution up to 100 km, and three distributions at higher altitudes. The three distributions shown indicate near-extreme conditions and an in-between, or average, situation. The range of variation can be seen to be very great, far more than a factor of 2 at the highest altitudes. The biggest portion of the variation is governed by the solar cycle, with the highest temperatures oc- curring near sunspot maximum. The constant temperature above about 300 km is frequently referred to as the exospheric temperature. The total amount of atmosphere above any location on the earth's surface at sea level, as indicated by the barometric pressure, is nearly constant (within about 5 per cent of its mean value); this near constancy apparently results from the mete- orological circulation of the lower atmosphere. The vertical extension of the atmos- phere is governed by its temperature and molecular weight. -
May 8-21, 1968 CHANGES in the LOWER EXOSPIDERE SINCE SOLAR Minm by Gerald M
GES IN THE LOWER EXOSPHERE SINCE SOLAR MTm By Gerald M. Keating NASA Langley Research Center Langley Station, Hampton, Va e GPO PRICE $ CSFTl PRICEtS) $ Presented at 9th COSPAR International Space Science Sp-posiwn Tokyo, Japan May 8-21, 1968 CHANGES IN THE LOWER EXOSPIDERE SINCE SOLAR MINm By Gerald M. Keating Measurements of atmospheric densities between 500 km and 750 km and between BOo latitude have been made by means of the Explorer XIX (1963-53A)and Explorer XXIV (1964-76A)satellites during the period of increasing solar activity (1964-1967) During this period the atmosphere has expanded due to increased solar heating to such an extent that near TOO km recent measurements indicate densities 30 times greater than were measured at minimum solar activity. Latitudinal-seasonal variations have changed during this period of increased solar heating. It was found that peak densities near 650 km have shifted from high latitudes in the winter hemisphere to low latitudes in the summer hemisphere. This change in latitudinal-seasonal variations confirms the prediction of Keating and Phor that at these altitudes with an increase in solar activity, the winter helium bulge would be dwarfed by an expanding summer atomic oxygen bulge. Xt is apparent that atomic oxygen has now replaced helium as the principal constituent near 650 km, After accounting for latitudinal-seasonal variations, a global semiannual and annual variation of atmospheric densities nearly as large as has been observed in the past becomes evident throughout the period of increasing solar activity. Unexpectedly low densities were observed in September of 1964, 1965, and 1966. -
Chapman Conferences
ABSTRACTS listed by name of presenter Alexander, M. Joan (between one day and one week apart). The stratopause temperature and height vary between observation nights on Mountain Wave Momentum Fluxes in the Southern scales of several kilometres and tens of Kelvin as a result of Hemisphere from Satellite Measurements planetary wave activity. The stratopause is also affected by Alexander, M. Joan1; Grimsdell, Alison1; Teitelbaum, Hector2 gravity-wave activity during the night, with the regular passage of inertia-gravity waves changing the stratopause 1. Colorado Research Associates Division, NWRA, Boulder, altitude by up to ~10km over the course of 18 hours. Gravity CO, USA wave dissipation above 40 km occurs during winter, while 2. LMD, Paris, France significant dissipation is only noted below the stratopause Accurate representation of stratospheric winds in the during autumn. Temporally filtered data with ground based Southern Hemisphere in climate models depends on the periods of 2 – 6 hours are examined in addition to the non- parameterization of gravity wave drag. Parameterization of filtered data, with similar seasonal cycles and short-term orographic wave drag is widely considered to be insufficient variability noted. We compare the seasonality of gravity-wave in these models, and additional drag from non-orographic energy with other high latitude sites and suggest that the waves is very important. Previous work has shown the main contribution to wave energy above Davis is from non- stratospheric circulation affects both the seasonal orographic sources. development of the ozone hole, and predicted changes in 21st century Southern Hemisphere climate. Recent Alexander, Simon observational evidence suggests that small islands in the The effect of orographic waves on Antarctic Polar Southern Ocean may be important sources of orographic Stratospheric Cloud (PSC) occurrence and wave drag that is currently missing in existing parameterizations. -
Environmental Impact of High Power Density Microwave Beams on Different Atmospheric Layers
Environmental impact of high power density microwave beams on different atmospheric layers T. R. Robinson, T. K. Yeoman and R. S. Dhillon, Radio and Space Plasma Physics Group, Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK. ESA Contract number: 18156/04/NL/MV CONTRACT REPORT The work described in this report was done under ESA contract. Responsibility for the contents resides in the author or organisation that prepared it. Environmental impact of high power density microwave beams on different atmospheric layers T. R. Robinson, T. K. Yeoman and R. S. Dhillon, Radio and Space Plasma Physics Group, Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK. ESA Contract number: 18156/04/NL/MV Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK. Francesco Cattaneo Andres Galvez Leopold Summerer Radio and Space Plasma Physics Group Tech. Rep. 63, Leicester University, UK, 2004. September 2004 CONTRACT REPORT The work described in this report was done under ESA contract. Responsibility for the contents resides in the author or organisation that prepared it. i Environmental impact of high power microwave beams Abstract The mechanisms involved in the trans-ionospheric propagation of Solar Power Satellite microwave beams are considered in the context of both efficiency of the power transfer as well as of environmental impact. Processes involved include, linear effects such as collisional absorption, scintillation and scattering which lead to loss of energy from the beam, as well as the excitation of certain nonlinear effects, such as stimulated scattering and the thermal self-focussing instability. -
Handbook of Correlative Data
THE NATIONAL SPACE SCIENCE DATA CENTER Handbook of Correlative Data FEBRUARY 1971 J41516 cxa XA *NATIONAL SPACE SCIENCE DATA CENTER NATIONAL AERONAUTICS AND SPACE ADMINISTRATION GODDARD SPACE FLIGHT CENTER, GREENBELT, MD. NSSDC 71-05 The National Space Science Data Center HANDBOOK OF CORRELATIVE DATA Joseph H. King, Editor February 1971 FOREWORD In previous years, the National Space Science Data Center (NSSDC) has generated a Catalog of Correlative Data. This catalog listed and, to some extent, described the correlative data holdings of NSSDC. How- ever, it was felt desirable to have a document of a more general nature, which would point to correlative data available at any data center or in any readily accessible publication. This Handbook of Correlative Data was generated to fulfill this need. This Handbook can be used to acquaint the reader with many solar and geophysical phenomena, to point the reader to more detailed discus- sions of the phenomena, and to direct him to the data. It is antici- pated that many readers will require this Handbook for only the last one or two of these purposes. A second edition of this Handbook will be generated when warranted. Accordingly, I would appreciate receiving comments from the users of this Handbook. Any recommendations for improving its usefulness will be most helpful in the generation of a second edition. I want to thank the NSSDC personnel who served as authors of the individual sections; their names appear on the pages introducing each of the nine major parts. I would like to acknowledge the assistance of other NSSDC personnel, particularly Miss Mary Anne Beeler, who were involved in the various stages of the generation of this Handbook. -
Interactions Between the Lower, Middle and Upper Atmosphere
Space Sci Rev (2012) 168:1–21 DOI 10.1007/s11214-011-9791-y Interactions Between the Lower, Middle and Upper Atmosphere Anne K. Smith Received: 2 February 2011 / Accepted: 30 May 2011 / Published online: 19 June 2011 © Springer Science+Business Media B.V. 2011 Abstract This survey of atmospheric regions is based on a presentation given at the Work- shop on Coupling between Earth’s Atmosphere and its Plasma Environment. The workshop was sponsored by the International Space Science Institute (ISSI) during September 2010. This survey begins with descriptions of aspects of the troposphere, stratosphere, and meso- sphere that affect vertical coupling. Then the tropopause, stratopause, and mesopause are considered, with a discussion of how they inhibit or allow the transmission of atmospheric mass or perturbations. Two transition interfaces are emphasized: the tropopause, which sep- arates the troposphere from the middle atmosphere, and the mesopause, which separates the middle atmosphere from the thermosphere. The survey of coupling processes looks at ra- diative processes, wave propagation, and mass exchange. Each topic includes one or more specific examples drawn from recent literature. Keywords Coupling · Solar variability 1 Introduction This article introduces the vertical structure of the atmosphere and discusses the interfaces between regions or layers. The focus is on the interactions across regions and the impedi- ments to interaction. Brief descriptions of the lower and middle atmosphere are given and the regions are contrasted. Several examples of coupling across regions are presented. The additional articles in this volume include detailed discussions of aspects of these interactions and other processes not discussed here. -
Change in Turbopause Altitude at 52 and 70◦ N
Atmos. Chem. Phys., 16, 2299–2308, 2016 www.atmos-chem-phys.net/16/2299/2016/ doi:10.5194/acp-16-2299-2016 © Author(s) 2016. CC Attribution 3.0 License. Change in turbopause altitude at 52 and 70◦ N Chris M. Hall1, Silje E. Holmen1,2,5, Chris E. Meek3, Alan H. Manson3, and Satonori Nozawa4 1Tromsø Geophysical Observatory, UiT – The Arctic University of Norway, Tromsø, Norway 2The University Centre in Svalbard, Svalbard, Norway 3University of Saskatchewan, Saskatoon, Canada 4Nagoya University, Nagoya, Japan 5Birkeland Centre for Space Science, Bergen, Norway Correspondence to: Chris M. Hall ([email protected]) Received: 5 May 2015 – Published in Atmos. Chem. Phys. Discuss.: 24 July 2015 Revised: 22 January 2016 – Accepted: 10 February 2016 – Published: 26 February 2016 Abstract. The turbopause is the demarcation between atmo- 1 Introduction spheric mixing by turbulence (below) and molecular diffu- sion (above). When studying concentrations of trace species in the atmosphere, and particularly long-term change, it may The upper mesosphere and lower thermosphere (UMLT) be important to understand processes present, together with regime of the atmosphere exhibits a number of features, the their temporal evolution that may be responsible for redis- underlying physics of which are interlinked and, relative to tribution of atmospheric constituents. The general region of processes at other altitudes, little understood. At high lati- transition between turbulent and molecular mixing coincides tude, the summer mesopause, around 85 km is the coldest with the base of the ionosphere, the lower region in which region in the entire atmosphere. The UMLT is, inter alia, molecular oxygen is dissociated, and, at high latitude in sum- characterised by the base of the ionosphere, dissociation of mer, the coldest part of the whole atmosphere. -
Gravitational Separation in the Stratosphere – a New Indicator of Open Access Atmospheric Circulation Biogeosciences Biogeosciences Discussions S
EGU Journal Logos (RGB) Open Access Open Access Open Access Advances in Annales Nonlinear Processes Geosciences Geophysicae in Geophysics Open Access Open Access Natural Hazards Natural Hazards and Earth System and Earth System Sciences Sciences Discussions Open Access Open Access Atmos. Chem. Phys., 13, 8787–8796, 2013 Atmospheric Atmospheric www.atmos-chem-phys.net/13/8787/2013/ doi:10.5194/acp-13-8787-2013 Chemistry Chemistry © Author(s) 2013. CC Attribution 3.0 License. and Physics and Physics Discussions Open Access Open Access Atmospheric Atmospheric Measurement Measurement Techniques Techniques Discussions Open Access Gravitational separation in the stratosphere – a new indicator of Open Access atmospheric circulation Biogeosciences Biogeosciences Discussions S. Ishidoya1, S. Sugawara2, S. Morimoto3, S. Aoki4, T. Nakazawa4, H. Honda5, and S. Murayama1 1National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8569, Japan Open Access 2Miyagi University of Education, Sendai 980-0845, Japan Open Access 3National Institute of Polar Research, Tokyo 190-8518, Japan Climate 4 Climate Center for Atmospheric and Oceanic Studies, Tohoku University, Sendai 980-8578, Japan of the Past 5Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA),of the Past Sagamihara 252-5210, Japan Discussions Open Access Correspondence to: S. Ishidoya ([email protected]) Open Access Earth System Earth System Received: 30 December 2012 – Published in Atmos. Chem. Phys. Discuss.: 20 February 2013 Dynamics Revised: 23 July 2013 – Accepted: 23 July 2013 – Published: 3 September 2013 Dynamics Discussions Abstract. As a basic understanding of the dynamics of the at- spheric components occurs in the atmosphere above the tur- Open Access Open Access mospheric circulation, it has been believed that gravitational bopause (about 100 km) (LewisGeoscientific and Prinn, 1984; Jacobs, Geoscientific separation of atmospheric components is observable only in 1999). -
Article, Whose Author Headed Juliusruh Station from 1965 to 2004
Hist. Geo Space Sci., 7, 1–22, 2016 www.hist-geo-space-sci.net/7/1/2016/ doi:10.5194/hgss-7-1-2016 © Author(s) 2016. CC Attribution 3.0 License. History of the Juliusruh ionospheric observatory on Rügen J. Weiß Leibniz-Institute of Atmospheric Physics e.V., University Rostock, Field Station Juliusruh, 18556 Altenkirchen, Germany Correspondence to: J. Weiß ([email protected]) Received: 30 August 2015 – Revised: 6 November 2015 – Accepted: 11 November 2015 – Published: 5 February 2016 Abstract. The history of the Juliusruh ionospheric observatory on Rügen is closely connected to the history of ground-based ionospheric sounding. After a short introduction to the ionospheric research and the sounding technique, the founding of the Juliusruh station in 1954 and its development until today are described. The different methods of ground-based sounding – as far as they apply to Juliusruh – are briefly discussed. The condition of life and work in a small team on the island of Rügen, remote from the respective parent institute, is also the subject of this article, whose author headed Juliusruh Station from 1965 to 2004. 1 Introduction sity maxima, starting at the bottom, were labelled D Region, E Region and F Region (Fig. 1). In addition to the regular flux of solar radiation, numerous The discovery of the ionosphere goes back to the year other factors affect the structure and dynamics of the iono- 1839, when the German mathematician and physicist Carl sphere. Among these factors are the geomagnetic field, the Friedrich Gauss postulated that an electrically conducting re- interplanetary magnetic field and the interplanetary flux of gion of the atmosphere could account for observed variations particles.