In this paper, we review the evolution of both, the concept and the operative methods of detection of Storm Commencements (SC's) and we introduce suggestions for future improvements. Finally, a more precise definition of the events with consequences in terminology and detection is proposed.

[1] Geomagnetic field data with high time resolution (typically 1 s) have recently become more commonly acquired by ground stations. Such high time resolution data enable identifying Pi2 pulsations which have periods of 40-150 s and irregular (damped) waveforms. It is well-known that pulsations of this type are clearly observed at mid-and low-latitude ground stations on the nightside at substorm onset. Therefore, with 1-s data from multiple stations distributed in longitude around the Earth's circumference, substorm onset can be regularly monitored. In the present study we propose a new substorm index, the Wp index (Wave and planetary), which reflects Pi2 wave power at low-latitude, using geomagnetic field data from 11 ground stations. We compare the Wp index with the AE and ASY indices as well as the electron flux and magnetic field data at geosynchronous altitudes for 11 March 2010. We find that significant enhancements of the Wp index mostly coincide with those of the other data. Thus the Wp index can be considered a good indicator of substorm onset. The Wp index, other geomagnetic indices, and geosynchronous satellite data are plotted in a stack for quick and easy search of substorm onset. The stack plots and digital data of the Wp index are available at the Web site (http://s-cubed.info) for public use. These products would be useful to investigate and understand space weather events, because substorms cause injection of intense fluxes of energetic electrons into the inner magnetosphere and potentially have deleterious impacts on satellites by inducing surface charging.

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Accurate measurements of the radiation delivered during the two largest solar flares ever observed are unavailable. In the case of the Carrington event (1858) the X-ray and UV radiation was not recorded, while in the case of the big flare which happened after the storm of 29-31 October 2003 we will call from now on as Halloween event (2003) the radiation saturated the X-ray radiometer. Despite many studies, a consensus regarding the real values of these events at the moment of maximum radiation has never been reached. In this paper, we used an alternative approach to try and determine these values. We estimated the values from the perturbations they produced in the Earth's magnetism -these are known as Solar Flare Effects (Sfe). Firstly, we established an empirical relationship between the variation in the radiation (cause) and its effect on the magnetism (consequence). Then, using the inverse function, we estimated the energy flux of both events. We found that both flares can actually be classified as being larger than X45. Finally, we also calculated the return period for a Carrington-like flare. Assuming that this event had an intensity of about X45 -according to our calculations -we estimated the return period to be 90 ± 60 years.