First International Conference on MOLDAVIAN RISKS – FROM ...

<strong>First</strong> <strong>International</strong> <strong>Conference</strong> on MOLDAVIAN RISKS - FROM GLOBAL TO LOCAL SCALE
16-19 May 2012, Bacau, Romania
SURLARI GEOMAGNETIC OBSERVATORY: ROLE INTO
SPACE AND EARTH WEATHER CONCEPT
Anca Isac 1 , Mioara Mandea 2 , Andrei Soare 1
1 Geological Institute of Romania, Surlari Geomagnetic Observatory
2 Centre National d'Etudes Spatiale, Earth Observation / Directorate for Strategy and Programmes
Corresponding author: Anca Isac, margoisac@yahoo.com
Abstract: Surlari (SUA) is the unique national magnetic observatory, established near the
capital, Bucharest, in 1943. Since then it is a research facility of the Geological Institute of
Romania. From 1997, SUA is member of the worldwide network of magnetic observatories -
INTERMAGNET, which monitors in real-time the Earth’s magnetic field variations. Space
weather reflects physical processes, beginning at the Sun’s surface, and can influence the
performance and reliability of space-borne and ground-based technological systems. Space
weather can threat human life or health too, according to the recent studies. The Sun emits
energy (flares of electromagnetic radiation: radio waves, infra-red, light, ultraviolet, X-rays)
and energetic electrically charged particles through coronal mass ejections. The
electromagnetic radiation travels at the speed of light and takes minutes to move from the Sun’
surface to the Earth, whereas the charged particles which travel outwards (the solar wind)
travel more slowly, taking from a few hours to several days to reach the Earth. Solar wind
interacts with the Earth's magnetic field and outer atmosphere in complex ways: concentrations
of energetic particles and electric currents flowing in magnetosphere and ionosphere. These can
result in geomagnetic more rapid variations opposite to the main geomagnetic field, which is
slowly varying and originates within the Earth. The ground-based magnetic observatories
provide a wide range of information, including the time and intensity of magnetic storms, substorms
and pulsations. Of particular importance for monitoring space weather conditions from
a ground observatory is the real-time observation of typical storms, which often start with a
“sudden commencement”, a positive perturbation in the horizontal magnetic field. The sudden
impulses (SI) usually exert no subsequent storms. The sudden storm commencements (SSC)
are followed by a general increase in the magnetic northward field as an initial phase (that may
continue minutes up to several hours), and after that the main and recovery storm magnetic
field pattern are observed, studied and sometimes subject of a warming alert. Scientists,
decision-makers from aeronautics and communication, and the public are informed about Sun-
Earth system phenomena that might impact human survival. A quantitative analysis of storm
time magnetic disturbance and the local geomagnetic disturbance index K are enabled every
three hours. One of the aims of SUA observatory is to reduce the impact of space weather on
activities of human interest on national territory, due to rapid processing and exchange of space
environment information. The field component variations are recorded at a sampling rate of 2
Hz and the field intensity at 0.2 Hz, continuously. A real-time plot showing 24 hours of the
current and previous day, including the delta-F check plot, is updated every 10 minutes. The
national geomagnetic observatory plays and will play a role in monitoring of space and Earth
weather conditions over Romanian territory, mainly nowadays when approaching the next solar
maximum, around 2013. This upcoming burst of solar activity, might affect mobile phones,
GPSs and many other modern technologies on Earth and near-Earth space. A network of
variometer stations to continuously monitor space weather might be a future project of SUA
observatory as well as a major involvement of it in the national and international space weather
programs.
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