Study on monitoring global warming by using the data of Schumann resonance

Identifying the global warming has become a more and more important issue for the present society and monitoring the global temperature is indispensable for measures against global warming. In this paper we use a long time record of the Schumann resonance (SR) intensity observed in Nakatsugawa, Japan and global lighting activity to study the global temperature change. SR is the electromagnetic resonance phenomenon in the earth-ionosphere waveguide driven by a cumulative effect of the global thunderstorm activity and observed anywhere on the earth round the clock. The cumulative magnetic field energy from the first and second modes of SR intensity for 4 years is derived for two horizontal components. The monthly dependence of field energy is compared with the global lightning and temperature data for the corresponding time period. As a result SR energy is found to be correlated well with the temperature in the middle latitude and global lightning activity especially in Africa. Further more the principal component analysis (PCA) is applied to extract the periodical component in each data set. The annual component of SR energy has a significant correlation with the middle latitude temperature, whilst the semi-annual component of the SR energy has a significant correlation with low latitude temperature.