000003819 001__ 3819
000003819 005__ 20190123122023.0
000003819 037__ $$aCTALK-2019-0027
000003819 100__ $$aDaglis, I. A.
000003819 245__ $$aLong-lived relativistic electron flux enhancement during a weak geomagnetic storm
000003819 260__ $$c2019
000003819 269__ $$c2019-04-08
000003819 520__ $$aThe relatively weak magnetic storm in April 2017, with SymH reaching only -50nT, resulted in a two orders of magnitude enhancement of relativistic and ultra relativistic electrons. This impressive enhancement is comparable to the St. Patrick’s event in 2015, an extreme storm with SymH reaching -235nT. The April 2017 enhancement appeared at energies up to 10 MeV, and was long-lived, lasting for more than 20 days. Nevertheless, the enhancement of super-relativistic electrons (6 MeV) was not recorded by geosynchronous spacecraft, which collect most of our space weather alert data. By analyzing radial profiles of PSD we show that the enhancement of relativistic and ultra–relativistic electrons is caused by different subsequent mechanisms: first, a series of intense substorms provided seed electrons and drove the growth of whistler mode chorus waves; second, the chorus waves accelerated the seed electron population to relativistic energies; third, the relativistic electrons were further accelerated to ultra–relativistic energies through inward diffusion driven by Pc5 ULF waves, which persisted throughout the magnetic storm duration.
000003819 594__ $$aSTCE
000003819 700__ $$aKatsavrias, Ch.
000003819 700__ $$aSandberg, I.
000003819 700__ $$aPodladchikova, O.
000003819 700__ $$aLi, W. 
000003819 700__ $$a3 , C.
000003819 700__ $$aPapadimitriou3
000003819 700__ $$a, C. Tsironis2,7and S. Aminalragia-Giamini3
000003819 773__ $$tEuropean Gephysical Union General Assembly, Vienna, Austria
000003819 8560_ $$felena.podladchikova@observatoire.be
000003819 906__ $$aContributed
000003819 980__ $$aCTALKCONT