Sunspot Maximum of 2025-a Foreboding of the Next Influenza Pandemic?

The majority of the pandemic influenza events of the last 450 years have occurred during periods of sunspot maxima. A review of this record suggests that there is a high probability that would have the next major influenza pandemic involving a new subtype of the virus ocurring during the next sunspot maximum (cycle 25) which is expected to occur during the years 2025 and 2026. We suggest strongly that preparatory action begins now, with a close monitoring of viral ingress into the stratosphere, as well as space weather monitoring using spacecraft resources

The cause of the appearance or disappearance of the Rieger-type periodicity in the northern and southern hemispheres of the sun

We use a continuous wavelet transform to analyse the daily hemispheric sunspot area data from the Greenwich Royal Observatory during cycles 12–24 and then study the cause of the appearance or disappearance of the Rieger-type periodicity in the northern and southern hemispheres during a certain cycle. The Rieger-type periodicity in the northern and southern hemispheres should be developed independently in the two hemispheres. This periodicity in the northern hemisphere is generally anti-correlated with the long-term variations in the mean solar cycle strength of hemispheric activity, but the correlation of the two parameters in the southern hemisphere shows a weak correlation. The appearance or disappearance of Rieger-type periodicity in the northern and southern hemispheres during a certain solar cycle is not directly correlated with their corresponding hemispheric mean activity strength but should be related to the strength of the hemispheric activity during sunspot maximum times, which hints the Rieger-type periodicity is more related to temporal evolution of toroidal magnetic field. The Rieger-type periodicity in the two hemispheres disappears in those solar cycles with relatively weak hemispheric activity during sunspot maximum times. The reason for the disappearance of this periodicity may be due to the combined influence of relatively weak toroidal magnetic fields and torsional oscillations, the differential rotation parameters vary through the solar cycle and may not remain more or less unchanged during some time, which does not permit the strong growth of magnetic Rossby waves.

Comment on ‘The Medieval Quiet Period’ – Implications arising from models of solar irradiance

The recent re-evaluation of sunspot data by Clette et al. strongly suggests that the total solar irradiance (TSI) values for the late 20th century were (apart from 1960) not significantly different from those of the periods of sunspot maxima in the 1780s and the 1840s–1860s in the latter part of the ‘Little Ice Age’. In effect, the re-evaluation removed the previously supposed sunspot maximum of the ‘modern’ period. That means that the supposed recovery of TSI levels to values significantly higher in the late 20th century than those of the ‘Medieval Quiet (or Warm) Period’ (Figure 1 of Bradley et al., 2016) must be an artefact of the solar data. Orbital data suggest that the northern hemisphere cooled significantly over the past 2000 years, a trend confirmed by global temperature proxies. Variations about that trend were driven by small variations in sunspot activity that led to the warmth of the ‘Medieval Quiet (Warm) Period’ and the subsequent cooling of the ‘Little Ice Age’. In fact, the ‘Little Ice Age’ contained several short warm periods when sunspots were at a maximum. It seems highly likely given the new sunspot calibration that the mid- to late 20th century warming was yet another of these ‘Little Ice Age’ warm episodes (e.g. no different from that in 1780) superimposed on which was a growing additional warming supplied by expanding emissions of greenhouses gases.

Some aspects of large-scale travelling ionospheric disturbances which originate at conjugate locations in auroral zones, cross the equator and sometimes encircle the earth

The occurrence of large-scale travelling ionospheric disturbances (LS-TIDs) has been examined. Initially some literature on their generation is considered. Travel during daylight hours and also paths which involve propagation paths towards the poles are illustrated by a few examples from the literature. A daytime ionogram recording of an LS-TID is presented and discussed as are nighttime ionogram recordings for a poleward path of propagation. The tabulations of Moscow h'F recordings around midnight are examined for significant height increases which along with geomagnetic bays some hours earlier confirm the existence of LS-TIDs. A sunspot-maximum interval is involved. Some of the Moscow events were related to bays which occurred 32 h earlier thus indicating earth encirclements. Also additional encirclements are recorded by using superposed-epoch analyses for some other events.

Space weather events in July 1982 and October 2003 and the effects of geomagnetically induced currents on Swedish technical systems

In this paper, we analyse in detail two famous space weather events; a railway problem on 13–14 July 1982 and a power blackout on 30 October 2003. Both occurred in Sweden during very intensive space weather storms and each of them a few years after the sunspot maximum. This paper provides a description of the conditions on the Sun and in the solar wind leading to the two GIC events on the ground. By applying modelling techniques introduced and developed in our previous paper, we also calculate the horizontal geoelectric field at the Earth's surface in southern Sweden during the two storms as well as GIC flowing in the southern Swedish 400 kV power grid during the event in October 2003. The results from the calculations agree with all measured data available. In the July-1982 storm, the geomagnetic field variation, ΔBx, reached values up to ~2500 nT/min and the geoelectric field reached values in the order of several volts per kilometer. In the October-2003 storm, the geomagnetic field fluctuations were smaller. However, GIC of some hundreds of amperes flowed in the power grid during the October-2003 event. Technological issues related to the railway signalling in July 1982 and to the power network equipment in October 2003 are also discussed.