Solar EUV measurements and ionospheric response



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The SolACES spectrometers continuously monitors the EUV/UV radiation of the sun in the wavelength range between 17 and 220 nm onboard the ISS (DLR, 2006). SolACES is part of the SOLAR space science instrument package. The instruments are directed towards the sun.

The primary scientific goal of SolACES is to observe the spectral irradiance of the sun and its variation with time. The spectral resolution of these measurements will vary between 0.5 and 2 nm depending on wavelength. A novel feature of SolACES is its capability to auto-calibrate the instrument during the mission. EUV fluxes are anticipated to be measured with an absolute radiometric accuracy of better than 10%.

A main goal of the project is to experimentally describe the response of the ionospheric electron density on mid-term solar flux changes. This requires the following analyses:

         Investigation of the solar irradiance and its variability in the EUV range based upon SolACES EUV measurements

         Investigation of the reaction of the neutral upper atmosphere composition, temperature and dynamics on variations in EUV flux using numerical models of the mesosphere/thermosphere

         Statistical study of the ionospheric response on EUV variations and EUV bursts using TEC data derived by ground and space based GPS measurements

         Modelling the time delay between EUV variations and the ionospheric response as indicated qualitatively by TEC time series

As a result, a comprehensive and detailed picture of the ionospheric response to EUV variations will be given. Co-products are a data base of EUV variations, EUV/TEC correlations, and numerical model results of the undisturbed and disturbed thermosphere/ionosphere system for the duration of the SolACES measurement campaign.


Publications within the project

The project bases on a cooperation between

Universitšt Leipzig,

DLR-Institute of Communications and Navigation, Neustrelitz,

Fraunhofer-Institute for Physical Measurement Techniques (IPM), Freiburg.

The SolACES project is led by IPM.


Related links:

         SolACES Summary

         SolACES home page

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Last modification 15.3.2011