Interplanetary Lyman alpha observations of SWAN during the rising phase of the 23rd solar cycle

T Summanen*, JTT Makinen, E Kyrola, W Schmidt, TI Pulkkinen, JL Bertaux, R Lallement, E Quemerais

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Abstract

In this work we show the development of the intensity pattern of the interplanetary Lyman a sky background radiation between 1996 and 1999 as measured by the SWAN instrument. The results show that the intensity pattern has changed considerably in three years. The pattern with two maxima in the northern and southern hemispheres observed in 1996 has developed to a pattern with only one maximum extending across the ecliptic plane. Earlier theoretical works have shown that a high ionization rate of interplanetary hydrogen atoms near the heliographic equator results in a pattern with two maxima, whereas an isotropic (constant as a function of latitude) ionization rate results in a pattern with one maximum. Thus, the change in the intensity pattern is most probably a signature of a more isotropic temporal average of the ionization rate, which is caused by a more isotropic temporal average of the solar wind proton flux during the rising phase of the solar cycle. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Original languageEnglish
Title of host publicationSTRUCTURE, ENERGETICS AND DYNAMICS OF THE CORONA AND THE HELIOSPHERE DURING THE RISING PHASE OF THE 23RD SOLAR CYCLE
EditorsS Gibson, ST Suess
Pages457-462
Number of pages6
Publication statusPublished - 2002
MoE publication typeA4 Article in a conference publication
EventE2 2/D2 2 Symposium of COSPAR Scientific Commission E - Warsaw, Poland
Duration: 1 Jul 20001 Jul 2000

Publication series

NameADVANCES IN SPACE RESEARCH
PublisherPERGAMON-ELSEVIER SCIENCE LTD
Volume29
ISSN (Print)0273-1177

Conference

ConferenceE2 2/D2 2 Symposium of COSPAR Scientific Commission E
CountryPoland
CityWarsaw
Period01/07/200001/07/2000
OtherHeld at the 33rd COSPAR Scientific Assembly

Keywords

  • WIND LATITUDE DISTRIBUTION
  • SOHO
  • FLUX

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