BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:A MAVERICK GLE: THE RELATIVISTIC SOLAR PARTICLE EVENT OF DECEMBER 13\, 2006 DTSTART;VALUE=DATE-TIME:20070706T170500Z DTEND;VALUE=DATE-TIME:20070706T171700Z DTSTAMP;VALUE=DATE-TIME:20260413T151041Z UID:indico-contribution-79-0-376@cern.ch DESCRIPTION:Speakers: Prof. BIEBER\, John (University of Delaware)\nGround Level Enhancements (GLE) are more likely to occur when the Sun is \nvery active. The most recent GLE was a maverick. It occurred near solar \nminim um\, but it was a large event by historical standards\, with a peak increa se \nexceeding 100% at some stations. This talk reports initial observatio ns and \nmodeling of the GLE of December 13\, 2006 based on data returned by \nthe “Spaceship Earth” neutron monitor network. Supported by NSF g rant ATM-\n0527878\, the Thailand Research Fund\, and a Post-doctoral Fell owship from \nMahidol University.\n\nhttps://indico.nucleares.unam.mx/even t/4/session/79/contribution/376 LOCATION:Merida\, Mexico Yucatan I (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/79/contribution/376 END:VEVENT BEGIN:VEVENT SUMMARY:SIGNIFICANT SOLAR PROTON EVENTS FOR FIVE SOLAR CYCLES (1954-2007) DTSTART;VALUE=DATE-TIME:20070706T171700Z DTEND;VALUE=DATE-TIME:20070706T172900Z DTSTAMP;VALUE=DATE-TIME:20260413T151041Z UID:indico-contribution-79-0-715@cern.ch DESCRIPTION:Speakers: Dr. SHEA\, Margaret (Emeritus\, Air Force Research L aboratory)\nUsing a solar proton database for the past five solar cycles ( 1954-2007) we \nhave determined the total solar proton fluence above 10 an d 30 MeV and the \nnumber of discrete events that occurred each cycle. We find: \n(1) The number of discrete events in cycles 19-22 were essentiall y the same\; \n(2) Cycles 20 and 21\,at the beginning of the space era\, w ere relatively benign \nwith respect to solar proton fluence\; \n(3) Appro ximately 15% of the total number of discrete events each cycle are \nGLEs\ ;\n(4) Cycle 23 has been the most active cycle since 1954. \n\nWe also fi nd that both the number of discrete events and the total fluence can \nbe associated with a relatively small number of solar active regions with eac h \nregion producing several large events (i.e. sequences of activity). T his is \nparticularly true with solar cosmic ray events (GLEs). Of the 70 GLEs between \n1942 and 2006\, 15 active regions have been associated wit h 36 individual \nrelativistic solar proton increases. Recent studies of historic events\, particularly \nthe geophysical phenomena from late Augus t to early September 1859 indicate \nthat these sequences of activity have occurred in the distant past.\n\nhttps://indico.nucleares.unam.mx/event/4 /session/79/contribution/715 LOCATION:Merida\, Mexico Yucatan I (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/79/contribution/715 END:VEVENT BEGIN:VEVENT SUMMARY:Analysis of the 20 January 2005 Ground Level Enhancement DTSTART;VALUE=DATE-TIME:20070706T172900Z DTEND;VALUE=DATE-TIME:20070706T174100Z DTSTAMP;VALUE=DATE-TIME:20260413T151041Z UID:indico-contribution-79-0-862@cern.ch DESCRIPTION:Speakers: Prof. MORAAL\, Harm (North-West University)\nObserva tions of the Ground Level Enhancement (GLE) of 20 January 2005 are\nused t o investigate a commonly observed\, but poorly understood feature of\nthis class of event. The Sanae neutron monitor observed three distinct peaks\n during this event. The observations were augmented by a neutron moderated\ ndetector\, from which we could determine that the first\, ephemeral peak had a\nharder spectrum than the remainder of the event\, while the Hermanu s monitor\nindicates that particles with energies up to 5 GeV were present in the first\npeak.\n\nThe axis of symmetry of the event is determined fr om the observations of a\nseries of other neutron monitors\, and this axis coincides with the\n(time-varying) direction of the HMF as measured by th e ACE spacecraft. Based\non a simple model of quasi-linear scattering theo ry\, it is shown that the\nsecond and third peaks need not be due to back- scatter effects as has been\nproposed previously\, but that the rich amoun t of detail in this GLE allows\none to deduce that there were two accelera tion regions: first at the flare\nsite in the lower corona\, and later the shock formed by the eventual CME.\nThis hypothesis is explored in the nex t paper.\n\nhttps://indico.nucleares.unam.mx/event/4/session/79/contributi on/862 LOCATION:Merida\, Mexico Yucatan I (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/79/contribution/862 END:VEVENT BEGIN:VEVENT SUMMARY:Two Acceleration Mechanisms for Ground Level Enhancements DTSTART;VALUE=DATE-TIME:20070706T174100Z DTEND;VALUE=DATE-TIME:20070706T175300Z DTSTAMP;VALUE=DATE-TIME:20260413T151041Z UID:indico-contribution-79-0-897@cern.ch DESCRIPTION:Speakers: Dr. MCCRACKEN\, Ken (University of Maryland)\nThe pr evious paper showed that particles in the 20 January 2005 GLE were\nprobab ly accelerated in two distinct regions. X- and gamma-ray observations\nof the RHESSI spacecraft identify these regions as a loop-like\, bipolar\nstr ucture in the lower corona which accelerates the particles on a short\,\ne phemeral time scale to several GeV in energy\, and the shock around the CM E\nemanating from the parent flare\, that later accelerates particles over \nlarger spatial and time scales\, but to lower energies.\n\nIt is noted t hat the anisotropic distributions of the radiation in two such\nephemeral GLE that occurred in 1960 and 1978 were very similar. Using these\nthree e vents as guidance\, it is shown that initial ephemeral enhancements\nhave been observed previously in at least nine\, and possibly in eleven GLE\nas sociated with solar flares west of 28º W on the solar disk\, leading us t o\npropose that the event of 20 January 2005 should be regarded as the def ining\nexample of the GLE\, namely that there are two separate acceleratio n episodes\nin the typical GLE: (a) acceleration directly associated with the flare\nitself in the lower corona\, and (b) acceleration by a supercri tical shock\ndriven by the associated CME\, at about 2.5 solar radii.\n\nh ttps://indico.nucleares.unam.mx/event/4/session/79/contribution/897 LOCATION:Merida\, Mexico Yucatan I (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/79/contribution/897 END:VEVENT BEGIN:VEVENT SUMMARY:Effects of the January 2005 GLE/SEP Events on Minor Atmospheric Co mponents* DTSTART;VALUE=DATE-TIME:20070706T175300Z DTEND;VALUE=DATE-TIME:20070706T180500Z DTSTAMP;VALUE=DATE-TIME:20260413T151041Z UID:indico-contribution-79-0-1009@cern.ch DESCRIPTION:Speakers: Dr. STORINI\, MARISA (INAF/IFSI-Roma)\nIt is known f rom long ago that solar energetic charged particles\, driven by the \ngeom agnetic field\, are able to produce ionization at different altitudes of t he \nterrestrial atmosphere. Moreover\, they can initiate catalytic cycles for the ozone \ndepletion\, involving NOx (N+NO+NO2) and HOx (H\, OH\, HO 2) components. \nNevertheless\, only in recent years it was possible to co mpare chemical models \ninvolving atmospheric minor components with satell ite data. In this work we \nlooked for effects of the GLE/SEP events occur red during January 2005 on the \nOH and HNO3 species of the atmosphere. Re sults show that there is a \nresponse on the minor atmospheric components\ , which is different in the winter \nand summer terrestrial hemispheres.\n \n\n*: This topic is faced for COST 724 Action and supported by the Italia n Antarctic \nResearch Program in the frame of Solar-Terrestrial Relations and partly \nperformed for a PhD thesis under development at Siena Univer sity/Dept. of \nEarth Science.\n\nhttps://indico.nucleares.unam.mx/event/4 /session/79/contribution/1009 LOCATION:Merida\, Mexico Yucatan I (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/79/contribution/1009 END:VEVENT BEGIN:VEVENT SUMMARY:Milagro and Climax Measurements of the 2005 January 20 GLE Particl e Spectrum DTSTART;VALUE=DATE-TIME:20070706T180500Z DTEND;VALUE=DATE-TIME:20070706T181700Z DTSTAMP;VALUE=DATE-TIME:20260413T151041Z UID:indico-contribution-79-0-1152@cern.ch DESCRIPTION:Speakers: Mr. MORGAN\, Trevor (University of New Hampshire)\nM ilagro is a ground-based TeV gamma-ray telescope in the Jemez mountains\nn ear Los Alamos NM. Designed to image TeV gamma-ray sources\, it is also\n sensitive to energetic solar particles above the local geomagnetic cutoff. \nIt sits relatively close to the Climax neutron monitor in Colorado. Bec ause\nof their geomagnetic proximity\, these two instruments can be jointl y used to\nconstruct a time-dependent spectrum for GLE events unaffected b y particle\nanisotropies. Modeling of the performance of both instruments to both\nisotropic and anisotropic particle distributions is underway and will be\nused to constrain the 2005 January 20 spectrum during the brief event onset\nas well as the abrupt decay. The multiple data channels in t he Milagro\ninstrument are also sensitive to large anisotropies. We prese nt ongoing\nresults of the spectrum and anisotropy of the 2005 January 20 GLE.\n\nhttps://indico.nucleares.unam.mx/event/4/session/79/contribution/1 152 LOCATION:Merida\, Mexico Yucatan I (Fiesta Americana) URL:https://indico.nucleares.unam.mx/event/4/session/79/contribution/1152 END:VEVENT END:VCALENDAR