TIGER-program for thermospheric-ionospheric geospheric research: Long-term measurement of solar EUV/UV fluxes for thermospheric-ionospheric (T/I) modelling and for space weather investigations Original Research Article

On 18/19 June 1998 the 1st TIGER Symposium was held in Freiburg/Germany. After presentation and discussion of 28 invited and contributed talks, the symposium agreed to establish a longterm TIGER Program within the framework of the SCOSTEP International Solar Cycle Study Working Group 1, Panel 2. This decision is based on the general agreement that, for thermospheric-ionospheric research as well as for a broad range of commercial applications in space, the improvement of existing thermospheric-ionospheric (T/I) models is absolutely necessary to meet scientific goals. There are a number of scientific questions underlying the goal of understanding solar EUV/UV variability such as what are the primary mechanisms by which solar ultraviolet (UV), extreme ultraviolet (EUV), and soft X-ray (XUV) irradiance variations affect terrestrial global climate change and/or weather and what is their significance? How does solar forcing compare with that from other sources such as increasing concentrations of radiatively-active gases and atmospheric aerosols? How sensitive is the Earthʹs climate to changes in solar radiation? What time scales of solar variability are significant to climate? How might solar variability in these wavelengths affect global warming projections? Are there signatures of solar influences in the upper atmosphere that are distinct from anthropogenic effects?