The study of geophysical processes in the cusp and its nearby magnetospheric regions — the mantle and the low-latitude boundary layer — is a crucial link in the chain of understanding the mechanism of solar-terrestrial relations. The magnetic conjugation of these regions with the high-latitude ionosphere permits the study of the solar wind-dayside magnetopause interaction via ground-observed ionospheric phenomena. The major topics covered are the dayside aurora in Spitsbergen, and the Alfven waves detected by an induction magnetometer as high-latitude geomagnetic Pc1 pulsations. The results presented establish a relation between the aurora and pulsation dynamics and the reconnection phenomenon which occurs at negative IMF B_z values and which is commonly accepted to be the most likely way for the solar wind energy to penetrate into the inner magnetosphere. The results also suggest that the Spitsbergen optical and magnetic measurements provide the possibility for the world scientific community to solve the major space weather problem of monitoring the replenishment of the energy expended in the course of magnetospheric substorms.

Keywords: cusp, reconnection, dayside auroras, pulsation Pc1 PACS: 94.05.Sd, 94.20.-у, 94.30.−d (all) DOI: 10.3367/UFNe.0185.201506j.0655 URL: https://ufn.ru/en/articles/2015/6/i/ 000361014200009 2015PhyU...58..612S Citation: Safargaleev V V, Sergienko T I, Safargaleev A V, Kotikov A L "Magnetic and optical measurements and signatures of reconnection in the cusp and vicinity" Phys. Usp. 58 612–620 (2015) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Received: 14th, April 2015, accepted: 25th, February 2015 Оригинал: Сафаргалеев В В, Сергиенко Т И, Сафаргалеев А В, Котиков А Л «Магнитные и оптические измерения и признаки пересоединения в области каспа» УФН 185 655–663 (2015); DOI: 10.3367/UFNr.0185.201506j.0655