This project will analyze 14C data to study long term changes in solar activity, as it relates to terrestrial climate. There are two pertinent components of solap activity: the solar wind and irradiance. The solar wind modulates the production of 14C and irradiance forces the carbon cycle. This project will investigate both measurements and theory. Measurement of decadal or bidecadal samples prevents observation of high frequency changes in solar activity such as the 11-year cycle or short-lived phenomena such as 14C production by solar flares. Hence, it was decided to measure the C isotopes in annual tree rings. The project will measure 195 samples to complete work on the Oort and Wolf Solar Minima and the intervening Medieval Solar Maximum. Additional measurements would be made to further resolve questions concerning the Schwabe cycle during the Maunder Minimum. Theoretical work would concentrate on analysis of the new data and continued study of data from the 10,000 year data bank. Efforts would be made to deconvolute the solar wind and irradiance components of 14C variance in order to achieve a better understanding of the Sun's role in modulating the production of 14C and forcing of climate. Plans include further study of the 14C-climate correlation.***
