Showing papers in "Journal of Atmospheric and Solar-Terrestrial Physics in 1999"

TL;DR: In this paper, the authors presented the strategy and algorithms related to such a preliminary product, its calibration with synthetic observations generated from the International Reference Ionosphere (IRI), and the comparison with TOPEX TEC data.

TL;DR: In this paper, the authors used amplitude scintillation measurements of L1 (1.575MHz) signals from GPS satellites at Ascension Island (14.45° W, 7.95° S; magnetic latitude 16° S) during February-April, 1998, to compare amplitude scints with fluctuations of the total electron content (TEC).

TL;DR: In this article, the directionality of quasi-monochromatic (QM) waves in the mesopause region is found to be highly anisotropic, especially during the solstices.

TL;DR: The accuracy of single-frequency ocean altimeters benefits from calibration of the total electron content (TEC) of the ionosphere below the satellite as discussed by the authors, and the accuracy of the ocean altimeter can be improved by calibrating the TEC.

TL;DR: In this paper, the authors used a meteor radar at Sheffield, U.K. (53°27′N, 1°35′W) between 30 June 1989 and 6 October 1994 to study the variability of tidal amplitudes and the possibility that this is caused by nonlinear interactions with planetary waves.

TL;DR: In this article, the authors compare the results of 6 medium frequency radars (MFRs) and the Global Scale Wave Model (GSWM) for 3-month seasons.

TL;DR: In this paper, a climate forcing of 0.3 W m−2 arising from a speculated 0.13% solar irradiance increase can account for the 0.6°C subsequent warming from 1900 to 1990, a scenario which time dependent GCM simulations replicate when forced with reconstructed solar irradiances.

TL;DR: In this paper, the total electron content (TEC) of the ionosphere over Europe and over three North American stations for the 6-11 January 1997 storm event was derived.

TL;DR: In this paper, the impact on climate of solar variability generally fall into four categories: lower atmosphere GCM experiments, in which enhanced solar activity is represented by changes in spectrally integrated solar constant, and the photochemical response of the middle atmosphere to enhanced solar ultraviolet.

TL;DR: The radio-holographic method was briefly described and tested by using data of 4 radio occultation events observed by the GPS/MET experiment on 9 February 1997 as discussed by the authors. But the results of the experiments were limited.

TL;DR: The TING model as discussed by the authors is an extension of the National Center for Atmospheric Researchs thermosphere-ionosphere general circulation model (NCAR-TIGCM), which runs on a UNIX workstation.

TL;DR: In this article, the authors used a multi-function regression analysis that allows for a continuous linear trend, for natural variability, and for sudden changes of the mean due to successive instrumental improvements.

TL;DR: In this paper, the authors investigated the long-term wind measurements carried out at 6 northern midlatitude sites (Saskatoon, Sheffield, Juliusruh, Collm, Obninsk, Kazan) to establish a climatology of the semidiurnal tide in the mesopause region for the narrow latitudinal range between 52°N and 56°N.

TL;DR: In this article, the authors combined satellite and ground-based observations from 2-11 November 1993 were combined in the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure to derive realistic time dependent global distributions of the auroral precipitation and ionosphericconvection.

TL;DR: In this paper, a three-dimensional TEC mapping algorithm using three independent constant density slabs stacked vertically to model the electron density, and compare with a more conventional two-dimensional approach using a single slab.

TL;DR: In this paper, the authors studied the time development of phase irregularities as a function of latitude and longitude of individual storms and concluded that the irregularities that are noted on trans-ionosphericpaths are therefore thought to be in both the E and the F layers with a combination of structured hard and soft electron precipitation and coupling initiating the turbulent activity.

TL;DR: In this article, the authors compare measurements of the ionospheric F region at Millstone Hill during the severe geomagnetic disturbances of 5-11 June 1991 with results from the IZMIRAN and FLIP time-dependent mathematical models of the Earths ionosphere and plasmasphere.

TL;DR: In this article, the authors reviewed the long-term variations of total solar irradiance during solar cycles 21 and 22 and concluded that, within the current accuracy and precision of the measurements, the minimum level of the Sun's irradiance is about the same for both solar cycles.

TL;DR: In this paper, an observed negative storm effect on 10 January and strong post-midnight N m F 2 increases on 7 and 8 January followed by a steep T e decrease down to T n are analyzed.

TL;DR: The Global Aspects of Plasma Structures (GAPS) Project 3.1 as discussed by the authors provides an overview of the progress made in high-latitude plasma structuring under two distinct configurations of the interplanetary magnetic field (IMF).

TL;DR: In this paper, the results of a Schumann resonance monitoring campaign held at Lehta observatory, Karelia, Russia during July-August 1998 were presented, which demonstrated advantages of the Poynting vector (PV) technique when studying the space-time dynamics of the worldwide thunderstorm activity from a single observatory.

TL;DR: In this article, the long-term trends of critical frequency (foF2) and peak height (hmF2), as measured by the ionospheric F2-layer, were analyzed for the 1958-1994 interval.

TL;DR: The most prominent feature of the global TEC maps is the feature corresponding to the equatorial anomaly as mentioned in this paper, which becomes wider in magnetic latitude and more pronounced in amplitude as the activity level increases.

TL;DR: In this paper, the authors focus only on the surface environment that can have a direct impact on our everyday life, such as variations in the stratospheric ozone layer that shields us from harmful ultraviolet radiation, and changes in global climate that can hinder or delay the detection of climate changes that might result from our own technological activities.

TL;DR: In this article, the authors compared the diurnal variations of the measured peak height for different seasons and levels of solar activity with those estimated from ionosonde M3000F(2) and IRI predictions.

TL;DR: In this paper, the seasonal and UT variations of the external current vortex were obtained by averaging through each month and UT, and the effects of the UT variation were removed by subtracting the averaged value of each UT for the geomagnetically quiet days of the month.

TL;DR: In this article, the NCEP/NCAR re-analyses were extended to the whole globe by means of the nCEP and NCAR reanalyses for the period 1968-1996.

TL;DR: In this paper, a summary of measurements made during the most recent solar cycle (number 22 extending from 1986 1996) with emphasis on the spectral range 120-300 nm is provided.

TL;DR: In this article, the authors quantify the variability of the atmospheric electric field which can be explained by global cloud-to-ground lightning activity through linear regression analysis, and apply it to simultaneous measurements of the ELF magnetic field at Sondrestromfjord, Greenland, for comparison.

TL;DR: In this article, the authors summarize the main features of the ionospheric F region as observed by the Sondrestrom, Millstone Hill, Arecibo, and Jicamarca incoherent scatter radars during the 1-5May, 1995 CEDAR Storm Study interval.