A model of the dynamics of magnetic storms is proposed which describes the effects of magnetospheric activity on irregularities at F layer heights for auroral and subauroral latitudes. For high latitudes the initial phase of the storm dynamics first affects auroral latitudes, and then the effects descend to what were subauroral and middle latitudes. The effects weaken as the convective electric field boundary moves equatorward. In the second stage of the storm, i.e., the recovery period, the ring current plays a leading role at subauroral latitudes. The ring current, which has acted as a reservoir for ionospheric and solar wind ions, decays. In this recovery phase the sources of energy producing the irregularities at subauroral latitudes are the ions in the ring current. This new synthesis of storm effects uses illustrations from a number of magnetic storms with observations ranging from December 1971 to March 1989, primarily in years of high solar flux. The data illustrate the concept of two stages of irregularity development. (1) The initial descent and weakening of the effects of the electric field changes and (2) ring current decay which produces the conditions for the generation of the irregularities at subauroral latitudes.
Denver-based Millennium Hotels & Resorts North America, and Kirkland, Wash.-based Noble House Hotels and Resorts are the latest hotel chains to suffer card-related, point-of-sale system cybersecurity incidents.For MHR, the breach involves food and beverage systems at 14 of its U.S. hotels and less than 5,000 cards. The hotel chain said in a press release it originally received notification of the incident by the Secret Service and took immediate steps to investigate, isolate and take down the card-processing elements of the affected POS systems.Subsequently, MHR received a warning from its third-party service provider, that it had detected and addressed malicious code in certain legacy POS systems, including those used by MHR. Millennium immediately adopted additional security measures as recommended by the third-party service provider. continue reading » 2SHARESShareShareSharePrintMailGooglePinterestDiggRedditStumbleuponDeliciousBufferTumblr
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