Sun, Solar Analogs and the Climate

The 34th Saas-Fee advanced course of the Swiss Society of Astronomy and Astrophysics (SSAA) took place from March 15 to 20, 2004, in Davos, on the subject of The Sun, Solar Analogs and the Climate. PresentlytheSwissmountainresortofDavosisprobablymostwellknown for hosting an event on globalization. However, it is because Davos also happens to be the seat of the Physikalisch-Meteorologisches Observatorium Davos and World Radiation Center, that this course on a global subject was hosted here. Exceptionally, the topic of this course was not purely astrophysical, but themembersoftheSSAAdecidedtosupportitallthesameduetothetimely topic of global warming and its possible link to solar variations. In these times of concern about global warming, it is important to und- stand solar variability and its interaction with the atmosphere. Only in this way can we distinguish between the solar and anthropogenic contributions to the rising temperatures. Therefore, this course addressed the observed va- ability of the Sun and the present understanding of the variability s origin and its impact on the Earth s climate. Comparing the solar variability with that of solar analog stars leads to a better understanding of the solar activity cycle and magnetic activity in general, and helps us to estimate how large the solar variations could be on longer time scales. Inspiteofthefantasticweatherandsnowconditionswhichreignedduring this week, the participants assiduously took part in the lectures. This is proof ofthehighqualityofthelecturesthatthethreespeakers,JoannaHaigh,Mike Lockwood and David Soderblom, delivered. We deeply thank them for their contributions and e?orts and hope that the readers will enjoy the book as much as we enjoyed their lectures.