Publication Date:
2023-09-06
Description:
A change in the length of meteorological summer seasons has been pointed out recently in connection with global warming: longer and hotter summers in the North Hemisphere (Wang et al., 2021). It has been demonstrated that the diurnal variation of Schumann resonance peak frequencies (SRPFs) in the vertical electric component, mainly driven by the changing distance of dominant lightning sources relative to the observer, is characteristic to the season (Sátori, 1996). It is therefore possible to define ‘electromagnetic’ (EM) seasons based on SRPF variations. SRPFs measured at Nagycenk, Hungary were used to study the variation of the length, start, and end of the North and South Hemisphere (NH/SH) summer seasons, in an electromagnetic sense, in the time period 1994-2016. In each year, diurnal SRPF variations were correlated with the all-year average diurnal curve of the most characteristic month of summer: July (NH) and January (SH). When the trend in the correlation coefficient approached (underwent) the limit 0.85, the start (end) of the corresponding season was registered. In agreement with earlier findings, our results show that the SH summer (140-170 days) is longer than the NH summer (100-140 days). However, in contrast to the findings based on temperature variation-associated thresholds for determining the start and end of the seasons, the EM NH summer did not exhibit a clear elongation in the examined time period. On the other hand, the SH summer season was lengthened by 10-15 days mostly due to the delay of its retreat.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
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