Research Spotlight: Low solar irradiance may not be the primary driver for the Little Ice Age

Abstract

Total solar irradiance (TSI), essentially a measure of the amount of light the Sun puts out, varies with the 11‐year sunspot cycle and influences Earth's climate, especially when TSI is notably higher or lower than its average values. It had been thought that TSI was especially low during a period known as the Little Ice Age, which began in the late seventeenth century and coincided with a period of unusually low sunspot activity known as the Maunder Minimum. However, Schrijver et al. now suggest that TSI during that period may not have been as low as previously thought. They analyzed direct measurements of solar magnetic activity during the recent 2008–2009 period of low sunspot activity, which they argue was similar to the activity level during the Maunder Minimum. (Geophysical Research Letters, doi:10.1029/2011GL046658, 2011)