World Library  


 
  • Cover Image

A Meteor Head Echo Analysis Algorithm for the Lower Vhf Band : Vol...

By: K. Nishimura; T. Terasawa; T. Nakamura; J. Kero; H. Miyamoto; C. Szasz

Description: National Institute of Polar Research (NIPR), 10-3 Midoricho, Tachikawa, 190-8518 Tokyo, Japan. We have developed an automated analysis scheme for meteor head echo observations by the 46.5 MHz Middle and Upper atmosphere (MU) radar near Shigaraki, Japan (34.85° N, 136.10° E). The analysis procedure computes meteoroid range, velocity and deceleration as functions of time with unprecedented accuracy and precision. This is crucial for estimations of meteoro...

Kero, J., Szasz, C., Nakamura, T., Meisel, D. D., Ueda, M., Fujiwara, Y., Terasawa, T., Miyamoto, H., and Nishimura, K.: First results from the 2009-2010 MU radar head echo observation programme for sporadic and shower meteors: the Orionids 2009, MNRAS, 416, 2550–2559, doi:10.1111/j.1365-2966.2011.19146.x, 2011.; Kero, J., Szasz, C., Nakamura, T., Meisel, D. D., Ueda, M., Fujiwara, Y., Terasawa, T., Nishimura...

Read More
  • Cover Image

A Brief History of the Development of Wind-profiling or Mst Radars...

By: T. E. Van Zandt

Description: Aeronomy Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado 80303, USA. The history of the development of the wind-profiling or MST radar technique is reviewed from its inception in the late 1960s to the present. Extensions of the technique by the development of boundary-layer radars and the radio-acoustic sounding system (RASS) technique to measure temperature are documented. Applications are described briefly, particularly ...

Read More
  • Cover Image

Rosetta Swing-by at Mars – an Analysis of the Romap Measurements i...

By: U. Auster; S. McKenna-lawlor; I. Richter; S. Simon; B. Langlais; A. Boesswetter; K. H. Glassmeier; M. Fränz; N. J. T. Edberg; R Lundin; U. Motschmann

Description: Institute for Theoretical Physics, TU Braunschweig, Germany. The Rosetta spacecraft flew by Mars at a distance of 260 km on 25 February 2007 during a gravity assist manoeuvre. During the closest approach (CA) the lander magnetometer ROMAP was switched on. The dataset taken during this swingby provides insight into the plasma environment around Mars: in addition to a pronounced bow shock crossing Rosetta recorded the signature of the pile up region ...

Acuña, M H., Connerney, J E P., Ness, N F., Lin, R P., Mitchell, D., Carlson, C W., McFadden, J., Anderson, K A., Reme, H., Mazelle, C., Vignes, D., Wasilewski, P., and Cloutier, P.: Global Distribution of Crustal Magnetization Discovered by the Mars Global Surveyor MAG/ER Experiment, Science, 284, 790–793, 1999.; Arkani-Hamed, J.: An improved 50-degree spherical harmonic model of the magnetic field of Mars derived from both high-altitude and low-altitude data, J. Geophy...

Read More
  • Cover Image

Theoretical Aspects of the Onset of Indian Summer Monsoon from Per...

By: J. Srinivasan; A. Chakraborty; R. S. Nanjundiah

Description: Department of Meteorology, Florida State University, Tallahassee, Florida, USA. A theory is proposed to determine the onset of the Indian Summer Monsoon (ISM) in an Atmospheric General Circulation Model (AGCM). The onset of ISM is delayed substantially in the absence of global orography. The impact of orography over different parts of the Earth on the onset of ISM has also been investigated using five additional perturbed simulations. The large differen...

Hahn, D G. and Manabe, S.: The role of mountains in the south Asian monsoon circulation., J. Atmos. Sci.\/, 32\/, 1515–1541, 1975.; Anthes, R A.: A cumulus parameterization scheme utilizing a one-dimensional cloud model, Mon. Weather Rev.\/, 105\/, 270–286, 1977.; Chakraborty, A., Nanjundiah, R., and Srinivasan, J.: Role of Asian and African orography on Indian summer monsoon., Geophys. Res. Lett.\/, 29\/, doi:10.1029/2002GL015522, 2002.; Chao, W C.: Multiple quasi equil...

Read More
  • Cover Image

Response of the Equatorial and Low-latitude Ionosphere During the ...

By: G. Crowley; P. R. Fagundes; Y. Sahai; F. Becker-guedes; J. A. Bittencourt; J. R. Abalde; W. L. C. Lima

Description: Centro Univ. Luterano de Palmas (CEULP), Universidade Luterana do Brasil (ULBRA), 77054-970 Palmas, TO, Brazil. A digital ionosonde, of the type known as Canadian Advanced Digital Ionosonde (CADI), has been in routine operation at São José dos Campos (23.2° S, 45.9° W; dip latitude 17.6° S), Brazil, since August 2000. A new CADI was installed at Palmas (10.2° S, 48.2° W; dip latitude 5.5° S), Brazil, in April 2002. The two CADIs are part of a new networ...

Read More
  • Cover Image

A Case Study of a Radially Polarized Pc4 Event Observed by the Equ...

By: W. Baumjohann; C. Othmer; K. H. Fornacon; K. H. Glassmeier; H. U. Auster; R. Cramm; E. Georgescu

Description: Institut für Geophysik und Meteorologie, Technische Universität, Mendelssohnstr. 3, D-38106 Braunschweig, Germany. A 16 mHz Pc4 pulsation was recorded on March 17, 1998, in the prenoon sector of the Earth's magnetosphere by the Equator-S satellite. The event is strongly localized in radial direction at approximately L = 5 and exhibits properties of a field line resonance such as an ellipticity change as seen by applying the method of the analytica...

Read More
  • Cover Image

Empirically Modelled Pc3 Activity Based on Solar Wind Parameters :...

By: J. Verő; J. Reda; K. Pajunpää; P. Sutcliffe; T. Raita; S. Lotz; B. Heilig

Description: Tihany Geophysical Observatory, Eötvös Loránd Geophysical Institute, Hungary. It is known that under certain solar wind (SW)/interplanetary magnetic field (IMF) conditions (e.g. high SW speed, low cone angle) the occurrence of ground-level Pc3–4 pulsations is more likely. In this paper we demonstrate that in the event of anomalously low SW particle density, Pc3 activity is extremely low regardless of otherwise favourable SW speed and cone angle. We re-i...

Anderson, B. J., Erlandson, R. E., and Zanetti, L. J.: A model of the Earth's distant bow shock, J. Geophys. Res., 97, 3089–3101, 1992.; Bishop, C. M.: Neural {N}etworks for {P}attern {R}ecognition, Oxford University Press, 1995.; Bol'shakova, O. V. and Troitskaya, V.: Relation of the IMF direction to the system of stable oscillations, Dokl. Akad. Nauk+ (Proceedings of the Russian Academy of Sciences), 180, 343–346, 1968.; Chen, L. and Hasegawa, A.: A theory of long-peri...

Read More
  • Cover Image

Latitudinal Extent of Large-scale Structures in the Solar Wind : V...

By: P. Riley; H. A. Elliott; D. J. McComas

Description: Southwest Research Institute, San Antonio, Texas, USA. Comparison of solar wind observations from the ACE spacecraft, in the ecliptic plane at ~ 1 AU, and the Ulysses spacecraft as it orbits over the Sun’s poles, provides valuable information about the latitudinal extent and variation of solar wind structures in the heliosphere. While qualitative comparisons can be made using average properties observed at these two locations, the comparison of spe...

Read More
  • Cover Image

Impact: an Implicit Time Integration Scheme for Chemical Species a...

By: P. A. Stott; G. D. Carver

Description: Centre for Atmospheric Science, Chemistry Department, Cambridge University, Lensfield Road, Cambridge, CB2 1EW, UK. The implicit time integration scheme of Stott and Harwood (1993) was proposed as an efficient scheme for use in three-dimensional chemical models of the atmosphere. The scheme was designed for chemistry schemes using `chemical families', in which species with short lifetimes are grouped into longer-lived families. Further study with more c...

Read More
  • Cover Image

Bifurcation of Jovian Magnetotail Current Sheet : Volume 24, Issue...

By: A. I. Ershkovich; P. L. Israelevich

Description: Department of Geophysics and Planetary Sciences, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Israel. Multiple crossings of the magnetotail current sheet by a single spacecraft give the possibility to distinguish between two types of electric current density distribution: single-peaked (Harris type current layer) and double-peaked (bifurcated current sheet). Magnetic field measurements in the Jovian magnetic...

Read More
  • Cover Image

A Quantitative Model of the Planetary Na+ Contribution to Mercury’...

By: D. C. Delcourt; A. Millilo; S. Orsini; T. E. Moore; A. Mura; S. Grimald; F. Leblanc; J.-j. Berthelier

Description: CETP-CNRS, Saint-Maur des Fossés, France. We examine the circulation of heavy ions of planetary origin within Mercury’s magnetosphere. Using single particle trajectory calculations, we focus on the dynamics of sodium ions, one of the main species that are ejected from the planet’s surface. The numerical simulations reveal a significant population in the near-Mercury environment in the nightside sector, with energetic (several keV) Na + densities ...

Read More
  • Cover Image

A Comparison Between Vega 1, 2 and Giotto Flybys of Comet 1P/Halle...

By: M. Volwerk; K. Szegö; M. Delva; D. Schmid; C. Koenders; I. Richter; K.-h. Glassmeier

Description: Space Research Institute, Austrian Academy of Sciences, 8042 Graz, Austria. Three flybys of comet 1P/Halley, by VEGA 1, 2 and Giotto, are investigated with respect to the occurrence of mirror mode waves in the cometosheath and field line draping in the magnetic pile-up region around the nucleus. The time interval covered by these flybys is approximately 8 days, which is also the approximate length of an orbit or flyby of Rosetta around comet 67P/Churyum...

Alfvén, H.: On the theory of comet tails, Tellus, 9, 92–96, 1957.; Bertucci, C., Mazelle, C., Crider, D. H., Vignes, D., Acuña, M. H., Mitchell, D. L., Lin, R. P., Connerney, J. E. P., Rème, H., Cloutier, P. A., Ness, N. F., and Winterhalter, D.: Magnetic field draping enhancement at the Martian magnetic pileup boundary from Mars global surveyor observations, Geophys. Res. Lett., 30, 1099, doi:10.1029/2002GL015713, 2003a...

Read More
  • Cover Image

Statistical Behavior of Foreshock Langmuir Waves Observed by the C...

By: D. A. Gurnett; K. Sigsbee; J. S. Pickett; E. Lucek; C. A. Kletzing; A. Balogh

Description: Department of Physics and Astronomy, 203 Van Allen Hall, University of Iowa, Iowa City, IA 52242, USA. We present the statistics of Langmuir wave amplitudes in the Earth's foreshock using Cluster Wideband Data (WBD) Plasma Wave Receiver electric field waveforms from spacecraft 2, 3 and 4 on 26 March 2002. The largest amplitude Langmuir waves were observed by Cluster near the boundary between the foreshock and solar wind, in agreement with earlier studies...

Read More
  • Cover Image

Read More
  • Cover Image

Azimuthal Magnetic Fields in Saturn’s Magnetosphere: Effects Assoc...

By: J. A. Wild; E. J. Bunce; S. W. H. Cowley

Description: Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK. We calculate the azimuthal magnetic fields expected to be present in Saturn’s magnetosphere associated with two physical effects, and compare them with the fields observed during the flybys of the two Voyager spacecraft. The first effect is associated with the magnetosphere-ionosphere coupling currents which result from the sub-corotation of the magnetospheric plas...

Read More
  • Cover Image

Analysis of the Seasonal Variations of Equatorial Plasma Bubble Oc...

By: M. C. Kelley; B. M. Ledvina; P. M. Kintner; J. J. Makela

Description: E.O. Hulburt Center for Space Research, Code 7607, Naval Research Lab., Washington, District of Columbia 20375, USA. Over 300 nights of airglow and GPS scintillation data collected between January 2002 and August 2003 (a period near solar maximum) from the Haleakala Volcano, Hawaii are analyzed to obtain the seasonal trends for the occurrence of equatorial plasma bubbles in the Pacific sector (203° E). A maximum probability for bubble development is seen i...

Read More
  • Cover Image

A Case Study of a Sporadic Sodium Layer Observed by the Alomar Web...

By: B. Williams; D. Heinrich; J. Stadsnes; H. Nesse; M. I. Sandanger; U.-p. Hoppe; M. Rietveld; E. Trondsen; W. Singer; U. Blum

Description: Norwegian Defence Research Establishment, Kjeller, Norway. Several possible mechanisms for the production of sporadic sodium layers have been discussed in the literature, but none of them seem to explain all the accumulated observations. The hypotheses range from direct meteoric input, to energetic electron bombardment on meteoric smoke particles, to ion neutralization, to temperature dependent chemistry. The varied instrumentation located on Andøya and...

Arnold, K. S. and She, C.-Y.: Metal fluorescence lidar (light detection and ranging) and the middle atmosphere, Contemporary Phys., 44, 35–49, 2003.; Batista, P. P., Clemesha, B. R., and Simonich, D. M.: Horizontal structures in sporadic sodium layers at 23° S, Geophys. Res. Lett, 18, 1027–1030, 1991.; Clemesha, B. R., Batista, P. P., and Simonich, D. M.: Concerning the origin of enhanced sodium layers, Geophys. Res. Lett., 16, 1267–1270, 1988.; Batista, P. P., Clemesha,...

Read More
  • Cover Image

Ion Sense of Polarization of the Electromagnetic Wave Field in the...

By: C. Krafft; B. Lundin

Description: Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation, Russian Academy of Sciences, Troitsk, Moscow Region, 142190, Russia. It is shown that the left-hand (or ion-type) sense of polarization can appear in the field interference pattern of two plane electron whistler waves. Moreover, it is demonstrated that the ion-type polarized wave electric fields can be accompanied by the presence at the same observation point of electron-type ...

Read More
  • Cover Image

How Did the Solar Wind Structure Change Around the Solar Maximum? ...

By: M. Kojima; T. Ohmi; M. Tokumaru; K. Hayashi; D. J. McComas; K. Fujiki; A. Yokobe; H. A. Elliott

Description: Solar-Terrestrial Environment Laboratory, Nagoya University, 3-13 Honohara, Toyokawa, Aichi, Japan. Observations from the second Ulysses fast latitude scan show that the global structure of solar wind near solar maximum is much more complex than at solar minimum. Soon after solar maximum, Ulysses observed a polar coronal hole (high speed) plasma with magnetic polarity of the new solar cycle in the Northern Hemisphere. We analyze the solar wind stru...

Read More
  • Cover Image

Long-term Trends in the Ionospheric F2 Region with Different Solar...

By: J. Mielich; J. Bremer

Description: Leibniz-Institute of Atmospheric Physics at the Rostock University, Schloss-Str. 6, 18225 Kühlungsborn, Germany. A new comprehensive data collection by Damboldt and Suessmann (2012a) with monthly foF2 and M(3000)F2 median values is an excellent basis for the derivation of long-term trends in the ionospheric F2 region. Ionospheric trends have been derived only for stations with data series of at least 22 years (124 stations with foF2 data an...

Alfonsi, L., de Franceschi, G., Perrone, L., and Materassi, M.: Long-term trends of the critical frequency of the F2 layer at northern and southern high latitude regions, Phys. Chem. Earth, 27, 607–612, 2002.; Bilitza, D., Sheikh, N. M., and Eyfrig, R.: A global model for the height of the F2-peak using M3000 values from CCIR, Telecommunication Journal, 46, 549–553, 1979.; Bencze, P.: Geographical distribution of long-term changes in the height of the maximum electron de...

Read More
 
1
|
2
|
3
Records: 1 - 20 of 45 - Pages: 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Fair are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.