ANALYSIS OF GEOMAGNETIC DATABASES IMPACTING SPACE WEATHER

Through the complex analysis of the geomagnetic database of the Surlari Geomagnetic Observatory for over 80 years, corroborated with the data of other planetary observatories from the INTERMAGNET network, we have extracted the geomagnetic information that is correlated with the specific physical parameters of space weather domain. Space weather refers to the conditions and phenomena occurring in outer space that can influence the near-Earth space environment. This concept includes a variety of events and conditions that occur outside the Earth's atmosphere and can affect various aspects of space activities and technology. At the same time, we used the Romanian geomagnetic database, regarding declination, inclination and the total geomagnetic field, made in ArcGIS based on measurements in Romanian airports. Correlating the historical geomagnetic data of the observatory with the Solar Cycles and variations of the solar emission, with the spatiotemporal evolution of the composition, density, speed of the solar wind and ionospheric effects, provides a tool for forecasting climate change, space weather and for rapidly quantifying the possible effects of extreme geomagnetic storms in mid-latitudes. The periodic update of absolute declination values from the Airport Secular Variation Network with the help of global models, national reference values determined from observatory records and in situ measurements highlights the dynamics of national declination anomalies in real time and represented a tool for risk assessment in a strategic field � National Air Traffic Security. In this paper, we present the Fourier and wavelet analysis of geomagnetic data recorded at different planetary observatories, regarding geomagnetic storms. Fourier analysis highlights the predominant frequencies of the magnetic field components. Wavelet analysis provides information about the frequency ranges of magnetic fields, which contain long time intervals for average frequency information and short time intervals for highlight frequencies, details of the analyzed signals. Also, wavelet analysis allows us to decompose geomagnetic signals into different waves. The presented analyzes are significant for the study of the geomagnetic storm. Data for the following days after the storm showed a weakening of the disturbances and a transition to quiet days of the geomagnetic field. In both, the Fourier Transform and the Wavelet Transform, the evaluation of the transform involves the calculation of a scalar product between the analyzed signal and a set of signals that form a certain basis in the vector space of finite energy signals. At the same time, we present in this paper the realization of the web-GIS application for the magnetic declination measurements carried out by the Surlari Geomagnetic Observatory in the period 2010-2023.