Villámok extrém alacsonyfrekvenciás sugárzásán alapuló új módszerek kidolgozása a
földközeli térs...(K138824) Támogató: NKFIH
Multi-station observations of Schumann resonance (SR) intensity document common behavior
in the evolution of continental-scale lightning activity in two super El Niño events,
occurring in 1997/98 and 2015/16. The vertical electric field component of SR at Nagycenk,
Hungary and the two horizontal magnetic field components in Rhode Island, USA in 1997,
and in 2014-2015, the two horizontal magnetic field components at Hornsund, Svalbard
and Eskdalemuir, United Kingdom as well as in Boulder Creek, California and Alberta,
Canada exhibit considerable increases in SR intensity from some tens of percent up
to a few hundred percent in the transition months preceding the two super El Niño
events. The UT time distribution of anomalies in SR intensity indicates that in 1997
the lightning activity increased mainly in Southeast Asia, the Maritime Continent
and India, i.e. the Asian chimney region. On the other hand, a global response in
lightning is indicated by the anomalies in SR intensity in 2014 and 2015. SR-based
results are strengthened by comparison to independent lightning observations from
the Optical Transient Detector and the World Wide Lightning Location Network, which
also exhibit increased lightning activity in the transition months. The increased
lightning is attributable to increased instability due to thermodynamic disequilibrium
between the surface and the mid-troposphere during the transition. Our main conclusion
is that variations in SR intensity may act as a precursor for the occurrence and magnitude
of these extreme climate events, and in keeping with earlier findings, as a precursor
to maxima in global surface air temperature. As a continuation of our research we
plan to set up a webpage dedicated to monitor the actual state of global lightning
activity based on SR measurements which may contribute to the early identification
of increased instability preceding the next super El Niño event.