Comparacion entre Valores de Vtec Predichos por el Modelo Nequick2 y los Obtenidos a Partir de Gps sobre Boulder durante muy baja actividad Solar

Una especificación confiable del estado de la ionósfera dada por modelos empíricos es importante para mitigar los efectos que esta zona atmosférica produce sobre las operaciones de los sistemas de posicionamiento y navegación basadas en satélites.Este estudio evalúa la capacidad del modelo NeQuick2 para predecir el contenido electrónico vertical total (VTEC), hasta la altura de los satélites GPS, sobre Boulder (40,00°N, 254,75°E), durante una época de muy baja actividad solar. Para ello se comparan las predicciones del modelo con valores de VTEC obtenidos a partir de señales de satélites GPS, publicados por el National Geophysical Data Center (NGDC) de EEUU.Teniendo en cuenta las incertezas de los valores de GPS VTEC publicados por el NGDC, los resultados muestran que el modelo estudiado, en general, se comporta como un buen predictor del contenido electrónico total en las condiciones solares consideradas.

Spatial Model of Sky Brightness Magnitude in KUSZA Observatory, UniSZA

Light pollution is the by-product of anthropogenic activities result from the increases in advanced economic and urbanization. Light pollution limits the ability to view the night sky by astronomers, on biodiversity, and ecosystems. This technology nowadays has led us to increase the convenient method to observe the brightness of night sky to determine how much the night sky polluted by artificial light. The study used SQM device and monitored the sky brightness of the KUSZA Observatory in Merang, Setiu, Terengganu, Malaysia. The results obtained were used to compare with the results obtained by simulation data generated from Earth Observation Group (EOG) of National Oceanic and Atmospheric Administration (NOAA), National Geophysical Data Center. It is the first world atlas of the artificial night sky brightness using GIS Interpolation tools. The result showed that the Kusza Observatory Merang is still appropriate to be the place of observation of celestial objects to either optical or radio astronomers. Hence, we recommended that through the data obtained from Defense Meteorological Satellite Program (DMSP) satellites, the value of sky brightness from all over the world can be used to make further analysis and to increase the precision of data recorded through observations. This study provides a clear view mapping of the accessing the sky condition using Geographic Information System (GIS) analysis in the study area.

Solar flares and variation of local geomagnetic field: Measurements by the Huancayo Observatory over 2001-2010

We study the local variation of the geomagnetic field measured by the Huancayo Geomagnetic Observatory, Peru, during 2001-2010. Initially, we sought to relate the SFI values, stored daily in the NOAA's National Geophysical Data Center, with the corresponding geomagnetic index; however, no relation was observed. Nonetheless, subsequently, a comparison between the monthly geomagnetic-activity index and the monthly SFI average allowed observing a temporal correlation between these average indices. This correlation shows that the effect of the solar flares does not simultaneously appear on the corresponding magnetic indices. To investigate this, we selected the most intense X-class flares; then, we checked the magnetic field disturbances observed in the Huancayo Geomagnetic Observatory magnetograms. We found some disturbances of the local geomagnetic field in the second and third day after the corresponding solar flare; however, the disturbance strength of the local geomagnetic field is not correlated with the X-class of the solar flare. Finally, there are some disturbances of the local geomagnetic field that are simultaneous with the X-class solar flares and they show a correlation with the total flux of the solar flare.

Some peculiarities in longitude distribution of sunspot groups over last four eleven-year solar cycles

This paper considers a longitude distribution of sunspot groups over 1982–2013, using data from the National Geophysical Data Center (Boulder, USA). The space-time distribution of sunspot groups is analyzed in coordinate sectors calculated from heliographic longitudes of the groups. A longitude extent of a coordinate sector is compared to the average size of one active region (30–40°). Then, in each coordinate sector, evolutionary activity of sunspot groups is summarized according to classification values after Malde throughout the observation period. The longitude distribution of large sunspot groups plotted in such a way does not reveal anticorrelation between Northern and Southern hemispheres in sunspot cycle 23.

Some peculiarities in longitude distribution of sunspot groups over last four eleven-year solar cycles

This paper considers a longitude distribution of sunspot groups over 1982–2013, using data from the National Geophysical Data Center (Boulder, USA). The space-time distribution of sunspot groups is analyzed in coordinate sectors calculated from heliographic longitudes of the groups. A longitude extent of a coordinate sector is compared to the average size of one active region (30–40°). Then, in each coordinate sector, evolutionary activity of sunspot groups is summarized according to Malde classification indices throughout the observation period. The longitude distribution of large sunspot groups made in such a way does not reveal anticorrelation between Northern and Southern hemispheres in sunspot cycle 23.

Crustal magnetic anomaly and Curie surface beneath Tarim Basin, China, and its adjacent area

Based on the geomagnetic field model NGDC-720-V3 (National Geophysical Data Center), the distribution of crustal magnetic anomalies and the Curie surface beneath Tarim Basin, China, and its adjacent area were investigated. The results show that the spatial distribution of the magnetic anomalies in Tarim Basin coincides with the regional tectonic structure, i.e., a basin sandwiched between mountain ranges. Shallow parts of the Curie surface are located in uplifted zones of the basin and correspond well to high values of heat flow. In contrast, deep parts of the Curie surface, having low values of heat flow, are distributed along the depression zones of the basin. The Curie point depth is consistent with the measured heat flow value, with a correlation coefficient of 0.65.

A statistical study on solar soft X-ray flare and the sources

We surveyed 28 year of Solar X-ray flares and sunspot group records supplied by the National Geophysical Data Center (NGDC) to study the dependence of different class Xray flares on the magnetic structure of sunspot groups statistically. It is found that 82.5% X-class flare, 51.4% M-class flare, 26.3% C-class flare, and 10.1% B-class flare occurred in the sunspot group with βγδ structure. There are 6.6% X-class flares, 17.5% M-class flare, 39.1% C-class flare, and 60.4% B-class flare occurred out of sunspot group.