FUPSOL

Finished ProjectsFUPSOL

Summary

FUPSOL (Future and Past Solar Influence on the Terrestrial Climate) was a Swiss collaboration project lead by PMOD/WRC involving partners from the Institute for Atmosphere and Climate Sciences of the ETH Zürich (IAC ETHZ), the Swiss Federal Institute of Aquatic Science and Technology, Dübendorf (EAWAG), the Physics Institute (KUP) and Institute of Geography (GIUB) of the University of Bern and the Oeschger Center for Climate Change Research. The project  aimed to study solar forcing and it’s influence on the Earth’s atmosphere, ozone layer and climate in the past and future. FUPSOL ended in March 2017. The main aims of all sub-projects were mostly fulfilled.

FUPSOL included several sub-projects:

  • The sub-project A  (“Calculating the time variable spectral solar irradiance for past and future based on solar activityproxies”)
  •  The sub-project B  (“Long-term simulations of the future climate with the standard and improved versions of the AOCCM model”)
  •  The sub-project C  (“Assessing the sensitivity of the atmosphere-ocean-chemistry system to different external forcing factors”)
  •  The sub-project D (“Solar effects on the tropospheric weather”)

Description of FUPSOL Sub-Projects

In sub-project A, using the Code for the High Spectral ResolutiOn recoNstructiOn of Solar irradiance model (CHRONOS), we completed the reconstruction of the spectral solar irradiance, covering the period from 6000 BCE to the end of the 21stcentury, by: i) applying an improved set of solar structure models, ii) modified treatment of the long-term irradiance evolution of the quiet sun, iii) a new calculation approach for the active region filling factors, iv) and several recently published solar modulation potential data sets. A comparison of the new SSI data sets with observations during the satellite era showed better performance when compared to our previous reconstruction (Egorova et al., 2018).

In the framework of the subproject “B”, we investigated the influence of auroral electron precipitation on the atmosphere using a new parameterisation of the NOy influx from the thermosphere. Our model results show that this approach showed good agreement of the simulated NOy enhancement and ozone depletion with measurements from satellite data. These results are presented by Arsenovic et al. (2017).

The subproject “C” was completed in 2015. The analysis of the sensitivity simulations with and without chemistry-climate interactions, which show the importance of interactive chemistry for climate change prediction, was published by Muthers et al. (2016).

The subproject “D” team analysed the influence of solar activity on European weather. A time series of daily weather types from MeteoSwiss was reconstructed back to 1763 (Schwander et al., 2017a). This novel weather type classification (CAP7) focuses on the Alpine region and Central Europe and is composed of 7 weather types. The influence of the 11-year solar cycle on European climate was analysed by Schwander et al. (2017b), which showed that the combination of changes in the occurrence of weather types and within-type differences led to colder temperatures over Central Europe under low phases of the 11-year solar activity. However, these results have not been found in our climate model results.

The general success of the FUPSOL project is reflected by the number of publications and citations since 2014, illustrated in Figure 1.

Figure 1. Total number of publications (upper panel) and citations (lower panel) relevant to FUPSOL. The data are from Thomson-Reuter’s Web of Science.

Results and Conclusions

More details on the FUPSOL project as well as the main results, conclusions and further references can be found in the scientific reports in the below links:

FUPSOL-1 Science Report

FUPSOL-2 Science Report

References

Arsenovic, P., Damiani, A., Rozanov, E., Funke, B., Stenke, A., and Peter, T. (2018), Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2018-1123, in review.
Egorova, T. et al., (2018), Revised historical solar irradiance forcing , Astron. Astrophys., 615, A85, https://doi.org/10.1051/0004-6361/201731199
Muthers, S. et al., (2016), Response of the AMOC to reduced solar radiation – the modulating role of atmospheric chemistry, Earth Syst. Dynam., 7, 877–892, https://doi.org/10.5194/esd-7-877-2016
Schwander, M. et al., (2017a), Reconstruction of central European daily weather types back to 1763, Int. J. Clim, https://doi.org/10.1002/joc.4974
Schwander, M. et al., (2017b), Influence of solar variability on the occurrence of Central European weather types from 1763 to 2009, Clim. Past Discuss., https://doi.org/10.5194/cp-2017-8
For further information please contact: Dr. Eugene Rozanov