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[en] Complete text of publication follows. This study presents an analysis of the evening F- region prereversal vertical drift variation over Brazil as a function of the solar flux (F10.7). The vertical drift is determined using true heights data obtained from ionograms recorded by digisondes operated at in Sao Luis (44.2 deg W, 2.33 deg S, dip angle: -2.7 deg) and Fortaleza (38.45 deg W, 3.9 deg S, dip angle: -11.5 deg). Data collected from October to December in the solar minimum years of 2006 and 2007 were used in the analysis. The results show that for both S?o Luis and Fortaleza the evening vertical drift significant dependence on solar flux variation, i.e., the vertical drift increases with the increase in solar flux. This results of vertical drift will compared with model IRI and are discussed from the perspective of validating the IRI model.
[en] The 10.7 cm solar radio flux (F10.7), provided by the National Research Council of Canada since 1947, is widely used as an index of solar activity and as a proxy for other solar quantities that are harder to measure. Over recent years needs have arisen that are difficult to meet with solar flux measurements at a single wavelength. F10.7 comprises contributions from multiple emission mechanisms. To separate these, multi-wavelength measurements are needed. A new instrument is under construction that will measure fluxes precisely in six bands at 2.8, 3.6, 6.0, 10.7, 18 and 21 cm.
[en] A line resolved (R = λ/Δλ ∼ 350,000-700,000) solar flux atlas covering the region ∼2958-9250 A is discussed. The atlas has been prepared from ground-based spectra. The telluric spectrum was derived from disk-center solar spectra taken at differing airmasses. This telluric spectrum was removed from the flux spectrum. Identifications are provided for solar lines. Both the data and plots with line identifications are available digitally.
[en] The authors report on measurements of the Hall and Pedersen conductances of the quiet time auroral ionosphere made using the EISCAT radar. They derive expressions for the conductances as a function of the 10.7cm solar flux (Sa) between 70 and 250 (x10-22Wm-2Hz-1), and the solar zenith angle χ. The results are consistent with the recent model results of Rasmussen et al, but at higher levels of solar activity give results higher than previous models
[en] Complete text of publication follows. Four years (2002-2005) of continuous accelerometer measurements taken onboard the CHAMP satellite (orbit altitude ∼400 km) present a unique opportunity to investigate the thermospheric zonal wind on a global scale. Recently we were able to relate the identified wave-4 structure in the zonal wind at equatorial latitudes to the influence of nonmigrating tides and in particular to the eastward propagating diurnal tide with zonal wavenumber 3 (DE3). The DE3 tide is primarily excited by latent heat release in the tropical troposphere in deep convective clouds and thus was not expected to be found at 400 km altitude. In order to investigate the mechanisms that couple the tidal signals all the way to the upper thermosphere we started a comparison with the thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM) developed at the National Center for Atmospheric Research (NCAR). Therefore, the model output was processed the same way as the satellite data. Initial results for June solstice show a good agreement between the model and the satellite data for the westward propagating tides. Yet the model is underestimating the eastward propagating zonal wavenumber 2 diurnal tide (DE2) which is quite prominent in the CHAMP data. Furthermore, the model predicts a solar flux dependence of the tides with increasing (decreasing) amplitudes for the westward (eastward) propagating tides with increasing solar flux level. We can confirm the dependence on the solar flux level for the nonmigrating tidal signatures in CHAMP data as well.
[en] Complete text of publication follows. The alarming effects observed on the Earth's climate (the melting of glacial ice caps, tornados, sea level rising etc.) required a well accepted agreement for reduction of the carbon dioxide emission. This was a partially satisfactory action but to reduce the anthropogenic activities an effective procedure demands a zero population growth and moreover a reforesting to fix the carbon constituent back to the earth's surface. The scientific grounds for our concern are presented in this work. They include hydrogen, oxygen and carbon chemistry, solar flux attenuation and major energy absorbers as well as transport of atmospheric constituents in the lower atmosphere. In particular alerts on the harmful problems caused by the destruction of the stratospheric ozone layer were voiced during the three last decades and are formalized in this work.
[en] In this study an empirical relationship between the incoming solar UV radiation and concurrently measured cloud cover at Bombay (19o01'N, 72o55'E), based on data pertaining to two year (1986-1987) period is established. It is compared with a similar relationship used elsewhere and found to differ in its form as well as in the regression coefficients. Possible reasons for this discrepancy are discussed. Conditions under which the two relationships agree are also examined. (author)
[en] With latest experimental data the solar neutrino problem enters new phase when crucial aspects of the problem can be formulated in an essentially (solar) model independent way. Original neutrino fluxes can be considered as free parameters to be found from the solar neutrino experiments. Resonance flavour conversion gives the best fit of all experimental results. Already existing data allow one to constraint both the neutrino parameters and the original neutrino fluxes. The reconciliation of the solution of the solar neutrino problem with other neutrino mass hints (atmospheric neutrino problem, hot dark matter etc.) may require the existence of new very light singlet fermion. Supersymmetry can provide a framework within which the desired properties of such a light fermion follow naturally. The existence of the fermion can be related to axion physics, mechanism of μ-term generation etc. (author). 37 refs
[en] Complete text of publication follows. In this talk I give a general overview of dynamics of the solar interior including the properties and origin of large scale flows (differential rotation and meridional flow) and their relevance for solar dynamo models. Special emphasis will be put on the flux-transport dynamo, which has gained significant interest over the past decade, mainly due to the fact that his class of models can explain the majority of the observed cycle features with a minimum amount of tuning. After a brief summary of the main properties of flux transport dynamos I will review the basic assumptions underlying these models and discuss their validity in view of results from 3D local and global MHD simulations as well as non-kinematic mean field models that consider the feedback of the Lorentz force on meridional flow and differential rotation.