Showing papers in "Journal of Atmospheric and Solar-Terrestrial Physics in 2001"

TL;DR: In this paper, modern fast digitization techniques and computer methods have been combined with both new and old theoretical approaches to permit construction of a new class of meteor radar, which can simultaneously stream data into memory, detect occurrences of meteors, and determine the location of meteor trails (range and angle), as well as find their radial drift speeds and decay times.

TL;DR: In this paper, the authors used ionosonde data from thirteen stations to study the day-to-day variability of the peak F2-layer electron density, NmF2, which they use to define quantitative descriptions of variability versus local time, season and solar cycle.

TL;DR: In this article, the authors discuss the key factors that control the ESF generation by generalized Rayleigh-Taylor instability process, such as the prereversal enhancement electric field (vertical drift) that is controlled by post-sunset zonal wind and longitudinal conductivity gradients, meridional/transequatorial winds, flux tube integrated conducitvities, and seed perturbations.

TL;DR: In this paper, the authors reviewed the development of the ideas from the 1960s that relate the source of electromagnetic ion cyclotron (EMIC) waves to the plasmapause.

TL;DR: In this paper, the F2-region response to a geomagnetic storm usually called a ionospheric storm is a rather complicated event, which consists of the so-called positive an negative phases, which have very complicated spatial and temporal behavior.

TL;DR: In this article, a model of the ionosphere response to seismic-related lower atmosphere disturbances is developed, which connects disturbances of the key ionosphere parameters with increase of atmospheric radioactivity and injection of charged aerosols into the atmosphere.

TL;DR: In this article, the electron densities of the D-region were determined from observations of VLF subionospheric amplitude changes and these enhancements were then related to the magnitudes of the X-ray fluxes measured by the GOES satellites.

TL;DR: In this article, a model is applied to study the disturbances in terms of diffusional charging of aerosol particles with special regard to the background plasma conditions, i.e., the electron/ion production rate and the coefficient of dissociative recombination which depends on the positive ion composition.

TL;DR: A frequency-domain interferometric imaging technique for a better knowledge of the vertical distribution of the atmospheric scatterers detected by MST radars is proposed and different methods, commonly used in antenna array processing, are first described within the context of application.

TL;DR: In this paper, the ionospheric response to magnetospheric storm events over Brazil was analyzed using the F-layer critical parameters h'F, hpF2 and foF2, from ionograms obtained at Fz and CP.

TL;DR: In this article, the authors review solar geophysical data relating to the great magnetic storm of 14-15 May 1921, with emphasis on observations of the low-latitude visual aurora.

TL;DR: In this article, the authors used incoherent scatter radar measurements from the Jicamarca Observatory to study the variability of equatorial F-region vertical plasma drifts and found that the day-to-day variability of the vertical drifts decreases with the increase of solar activity for all seasons.

TL;DR: In this article, the GFZ has started the GPS Atmosphere Sounding Project (GASP) on using ground-based and space-based GPS observations for applications in the numerical weather predictions, climate research and space weather monitoring.

TL;DR: In this article, high-quality synoptic observations of the solar corona, as carried out by the EIT and LASCO experiments on SOHO, provide near real-time imaging of CMEs from the base of the corona out to a projected distance of 30 R ⊙ (R ⊆ is the solar radius).

TL;DR: In this article, the authors derived profiles of electron density fluctuations for the mesosphere/lower thermosphere region with a height resolution of around 1 km using GPS/MET data.

TL;DR: In this paper, the authors compare the time fluctuations at various distances from totality on the eclipse and adjacent days, inside a 5° West to 5° East longitude area, and show the expected longitude transit of eclipse perturbation.

TL;DR: The dominant interplanetary phenomena causing intense magnetic storms are the inter-planetary manifestations of fast coronal mass ejections (CMEs) as mentioned in this paper, and two interplan planetary structures are important for the development of such class of storms, involving an intense and long duration B s component of the IMF: the sheath region just behind the forward shock, and the CME ejecta itself.

TL;DR: An extra long period (20-40 day) oscillation has been identified in the mesospheric and lower thermospheric (60-100 km) winds observed simultaneously by radars (MF, LF) at four sites from 70°N to 30°N in the northern hemisphere during the winter of 1995/1996.

TL;DR: In this paper, the authors used measured lightning frequency, and correlated these records with other parameters characterising solar activity, namely Ap, F10.7 and cosmic ray flux, and obtained a significant correlation of lightning frequency with Ap and R, and a significant anti-correlation with cosmic rays flux.

TL;DR: In this paper, the effect of local anthropogenic air pollution on the fair weather atmospheric electric measurements at Marsta is estimated according to Sheftel et al, 1994a (J Geophys Res 99, 10,793) by comparing the Sunday and weekday values of air conductivity.

TL;DR: In this article, the quasi-2-day planetary wave over a period of two years with the medium frequency (MF) radar operated at Tirunelveli (8.7° N, 77.8° E ), India, is studied in detail.

TL;DR: In this article, the authors presented data from first global positioning system (GPS) measurements of global response of the ionosphere to solar flares of September 23, 1998 and July 29, 1999 and found that fluctuations of total electron content (TEC) obtained by removing the linear trend of TEC with a time window of about 5 min, are coherent for all stations and the line of sight to the GPS satellites on the dayside of the Earth.

TL;DR: In this article, short-term changes of electron concentration in the ionospheric F-region have been studied during a campaign of rapid sequence vertical ionosphere sounding and the most probable source of the observed waves was below the 175 km level and probably not in the auroral zone.

TL;DR: In this article, the authors model numerically the ionisation created in the mesosphere above a strong horizontal (cloud-to-cloud) lightning discharge, and thus to understand better the formation of columniform (spatially structured) sprites.

TL;DR: In this article, a comparison between the zenith path delay (ZPD), obtained from GPS measurements, and the expected delay, derived from models used to compensate tropospheric effects on SAR interferograms, is made.

TL;DR: Significant charged-particle precipitation occurs in the dayside auroral zone during and after interplanetary shock impingements on the Earth's magnetosphere as discussed by the authors, which represents direct solar wind energy input into the magnetosphere/ionosphere system.

TL;DR: In this paper, atmospheric experimental data which supports previous laboratory evidence of radiolytic particle formation is presented, showing increases in surface condensation nuclei (CN) which correlate positively with increasing in surface ionisation.

TL;DR: In this article, a unique multispectral imager and an associated multi-spectral analysis framework are described which together constitute a new diagnostic tool for auroral research, which uses two spectral bands (centered at 4278 and 7325 A) to extend the effective dynamic range of passive imaging to much lower energies.

TL;DR: In this article, the impact of ground-based GPS water vapour estimates in meteorological forecasting applications was evaluated using 10 months of GPS data from a selection of stations, which are co-located with radiosonde launch sites, within the UK permanent GPS network.

TL;DR: In this paper, the authors describe the formation of a knee in the cross-L plasma density distribution along the drift shell which is tangent to a surface called the Roche limit surface or zero-parallel-force surface.