%0 Journal Article
%@holdercode {isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S}
%@nexthigherunit 8JMKD3MGPCW/3EU29DP
%@resumeid 8JMKD3MGP5W/3C9JJ4U
%@archivingpolicy denypublisher denyfinaldraft24
%@usergroup administrator
%@usergroup simone
%3 solar terrestrial effects.pdf
%X The occurrence frequencies or fluxes of most of the solar phenomena show a 11-year cycle like that of sunspots. However, the average characteristics of these phenomena may not show a 11-year cycle. Among the terrestrial parameters, some related directly to the occurrence frequencies of solar phenomena (for example, ionospheric number densities related to solar EUV fluxes which show 11-year cycle like sunspots) show 11-year cycles, including the double-peak structures near sunspot maxima. Other terrestrial parameters related to average characteristics may not show 11-year sunspot cycles. For example, long-term geomagnetic activity (Ap or Dst indices) is related to the average interplanetary solar wind speed V and the total magnetic field B. The average values of V depend not on the occurrence frequency of ICMEs and/or CIRs as such, but on the relative proportion of slow and high-speed events in them. Hence, V values (and Ap values) in any year could be low, normal or high irrespective of the phase of the 11-year cycle, except that during sunspot minimum, V (and Ap) values are also low. However, 23 years after the solar minimum (well before sunspot maximum), V values increase, oscillate near a high level for several years, and may even increase further during the declining phase of sunspot activity, due to increased influence of high-speed CIRs (corotating interplanetary regions). Thus, Ap would have no fixed relationship with sunspot activity. If some terrestrial parameter shows a 11-year cycle, chances are that the solar connection is through the occurrence frequencies (and not average characteristics) of some solar parameter.
%N 12
%T Solar terrestrial effects of two distinct types
%@secondarytype PRE PI
%K Solar parameters, Sunspot cycle, Interplanetary parameters, Terrestrial parameters.
%@visibility shown
%@group DGE-INPE-MCT-BR
%@secondarykey INPE-14991-PRE/9902
%@copyholder SID/SCD
%@issn 0273-1177
%2 sid.inpe.br/mtc-m17@80/2007/11.27.13.35.16
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%B Advances in Space Research
%P 1890-1897
%4 sid.inpe.br/mtc-m17@80/2007/11.27.13.35
%D 2007
%V 39
%@doi 10.1016/j.asr.2007.02.006
%A Kane, Rajaram Purushottam,
%@dissemination WEBSCI; PORTALCAPES; MGA; COMPENDEX.
%@area CEA