Showing papers in "Journal of Atmospheric and Solar-Terrestrial Physics in 2004"

TL;DR: The inner workings of the Lyon–Fedder–Mobarry (LFM) global magnetospheric simulation code is described, giving a rough blueprint of how to build a similar simulation model.

TL;DR: In this article, the authors considered the current drivers of the observed ion and electron drifts in the low and middle latitudes of the ionosphere and provided an overall understanding of the governing principles.

TL;DR: In this paper, Wang et al. used the simple physics and empirical based Wang-Sheeley-Arge (WSA) model driven by two different sets of updated photospheric field synoptic maps to accomplish this: daily updated maps from Mount Wilson Solar Observatory and updated SOHO/MDI maps constructed with the Schrijver et al flux transport data assimilation algorithm.

TL;DR: The communication/navigation outage forecasting system (C/NOFS) mission of the Air Force Research Laboratory as discussed by the authors is the first satellite solely dedicated to forecasting ionospheric irregularities and radio wave scintillations.

TL;DR: In this paper, the two major tropical continental zones of active convection (Africa and South America) are compared from the standpoint of lightning activity, rainfall, thermodynamics, hydrology and aerosol-influenced cloud microphysics.

TL;DR: The Coupled Magnetosphere Ionosphere Thermosphere (CMIT) model as discussed by the authors combines the Lyon-Fedder-Mobarry global magnetohydrodynamic (MHD) magnetospheric (LFM) model with the thermodynamic energy equations for the global thermosphere and ionosphere.

TL;DR: In this article, the effects of solar flares on the D-region electron densities were investigated using the NOSC Earth-ionosphere waveguide programs (LWPC and ModeFinder) over a wide range of VLF frequencies.

TL;DR: In this paper, the authors apply five different fitting techniques to two hypothetical time series derived from MHD simulation results, for which no information, other than the time series, was provided, and infer the following: accuracy decreases with increasingly glancing encounters; Correct identification of the boundaries of the flux rope can be a significant limiter; and results from techniques that infer global morphology must be viewed with caution.

TL;DR: In this paper, the authors present results on the coupling of coronal and heliospheric numerical magnetohydrodynamic (MHD) codes developed within the Center for Integrated Space weather modeling.

TL;DR: In this article, the authors employ a linear model of the responses to local body forces to estimate the spectra of gravity waves arising due to vertical motions within mesoscale convective complexes (MCCs) at equatorial latitudes.

TL;DR: In this paper, the authors presented simulation results from the coupled magnetosphere-ionosphere-thermosphere (CMIT) model under solar minimum, northern hemisphere summer conditions, and compared the simulated results of the CMIT model and those of the stand-alone TING model.

TL;DR: In this paper, the authors elaborate on the complex interplay between the magnetosphere and the polar regions, with an emphasis on the polar aeronomic behavior and its influence on the magnetospheric sources.

TL;DR: In this paper, the ionospheric total electron content (TEC) in the equatorial anomaly region is studied by analyzing dual-frequency signals from the global position system (GPS) acquired from a meridional chain of 9 observational sites clustered around Taiwan (21.9°-26.2°N, 118.4°-121.6°).

TL;DR: In this paper, high-intensity, long-duration, continuous AE activity (HILDCAA) is defined as magnetic reconnection between southward components of interplanetary Alfven waveuctuations and magnetopause magneticelds.

TL;DR: In this paper, the differences between solar maxima and minima in the zonal mean temperature through the depth of the troposphere, OLR, tropospheric vertical motion, and tropopause temperature are consistent with differences in the rainfall.

TL;DR: The spectral characteristics of the Schumann Resonance (SR) modes are defined by their resonant mode amplitude, center frequency and half-width (Q-factor) as discussed by the authors.

TL;DR: In this article, a rank order correlation coefficient (ROCC) analysis between ground-based 1-10 mHz ultra-low frequency (ULF) wave power, upstream solar wind speed (v SW ), and MeV electron flux across the outer radiation belt is presented.

TL;DR: In this article, the authors describe the issues and techniques that CISM will use to provide a physical space radiation model, which is used to provide advanced knowledge of significant variations in the highly energetic particle populations that form the Earth's radiation belts.

TL;DR: In this paper, the authors used the differential energy spectrum of cosmic rays obtained from the worldwide neutron monitor network since 1951 and taking into account also the slow changes in the geomagnetic dipole, calculated the corresponding 3D equilibrium ion concentration in the lower atmosphere as a function of time for the period 1951-2000.

TL;DR: In this paper, the authors present the results of a continuing study that utilizes a ground-based digital sounder at the magnetic equator to provide a "forecast" of the subsequent occurrence of scintillation activity and a network of UHF and L-band receivers that measure the S4 index, on a night-to-night basis.

TL;DR: In this paper, the authors examined the evolution of stationary planetary waves and nonmigrating diurnal tides in the lower mesosphere during November 1978-May 1979, based on a newly released, version 6 of the Nimbus 7 LIMS dataset.

TL;DR: In this article, a model for electron energy distribution incorporating electron acceleration by stochastic gyroresonance with whistler-mode chorus, and electron loss by precipitation due to pitch-angle scattering by plasma waves is proposed.

TL;DR: In this paper, the short-term effects of the energetic solar proton events (SPE) on the different characteristics of the lower atmosphere were studied in the North Atlantic region, which is an area of intensive cyclone genesis and development.

TL;DR: In this article, a long-term correlation study between solar and geomagnetic activity is reported using annual averages of the aa index and of the sunspot number R z in the period of 1868-2000.

TL;DR: In this paper, a meteor radar at Cachoeira Paulista, Brazil (22.7°S, 45°W) was used to measure the zonal and meridional winds in the region of the upper mesosphere and lower thermosphere (MLT) during two years, from March 1999 to February 2001.

TL;DR: In this paper, a new study of the geographical variation of the correlation between low cloud and predicted ionization level from cosmic rays at an altitude of 2 km was made and the correlation is strongest over the North and South Atlantic.

TL;DR: In this article, a new perspective of the planetary-scale sensible heat budget of the upper mesosphere/lower thermosphere was presented, and the importance of the wave entropy flux was stressed, an effect which is ignored in customary gravity wave parameterizations for global circulation models.

TL;DR: In this paper, the authors discuss the expected radar scattering cross-sections (RCSs) of head-versus trail-echoes and how equilibrium concepts such as plasma frequency are of limited use in describing the results.

TL;DR: In this paper, the authors presented two tables of cosmic ray (CR) events as a function of geomagnetic activity, indicating 19% of CR decreases without Dst variability and 28% of Dst variabilities without clear CR decreases, may be useful for investigating the relation between CR flux values and atmospheric effects.

TL;DR: In this paper, the role of variations in composition in linking the physical and chemical processes is discussed and examples from numerical models and observations are given to illustrate the points of importance of composition in mesopause temperature extremes.