The minimum between cycle 23 and 24: Is sunspot number the whole story?
De Toma, G., Gibson, S., Emery, B. A., & Arge, C. N. (2010). The minimum between cycle 23 and 24: Is sunspot number the whole story? Soho-23: Understanding A Peculiar Solar Minimum, 428, 217-222.
During recent years we have observed a long and deep solar minimum with sunspot number in 2008 and 2009 reaching the lowest level in about a century. In spite of the lack of sunspot activity at the Sun, observations have shown that a relatively complex corona and heliosphere persisted for most of... Show moreDuring recent years we have observed a long and deep solar minimum with sunspot number in 2008 and 2009 reaching the lowest level in about a century. In spite of the lack of sunspot activity at the Sun, observations have shown that a relatively complex corona and heliosphere persisted for most of the minimum phase. The solar corona did not reach the simple "dipolar" shape often seen during solar minima, while low-latitude coronal holes, and their associated corotating high-speed solar wind streams, persisted to 2008, modulating the solar wind. We compare the current and previous minima to show how, even during very quiet times, different magnetic configurations are possible at the Sun and discuss how these different morphologies can affect the corona, heliosphere, and even the geospace. Show less
