The effects of solar variability on the Earth's climate

• DOI: 10.1098/rsta.2002.1111
• Publication Date: 2003-03-06T02:19:47Z
• Authors: Joanna D. Haigh
• Keywords: Solar constant; Solar variation; Solar maximum

The absolute value of total solar irradiance is not known to better than ca.0.3% but measurements from satellite instruments over the past two cycles have shown that it varies by ca.0.1% on this time-scale. Over longer periods its has been reconstructed using proxy measures activity, and these suggest during Maunder minimum in activity late 17th century was 3−4 W m−2 lower at present. Observational data Sun influenced temperatures decadal, centennial millennial time-scales, radiative forcing considerations results energy-balance models general circulation warming latter part 20th cannot be ascribed entirely effects. However, chemical dynamical processes middle atmosphere may act amplify impact. An analysis zonal mean temperature shows effects differentiated those associated with other factors such as volcanic eruptions El Niño Southern Oscillation.