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We are currently observing the minimum phase of Cycle 23. Magnetic activity during the years 2006–2009 has been very weak with sunspot numbers reaching the lowest values in about 100 years. This long and extended minimum is characterized by weak polar magnetic fields, small polar coronal holes, and a relatively complex coronal morphology. This magnetic configuration at the Sun is remarkably different from the one observed during the previous two solar minima. We review observations made at the Sun and in the solar wind during the recent solar minima and discuss the implications of the observed differences for the heliosphere and geospace. [ABSTRACT FROM AUTHOR]

The past three years have been characterized by very weak sunspot and CME activity making this a long and deep solar minimum. In spite of the lack of magnetic activity at the Sun, white light and EUV images have shown that a relatively complex corona with multiple streamers and low latitude coronal holes persisted during most of this extended minimum. At the same time, solar wind observations indicated that the heliospheric current sheet was more warped during the declining and minimum phase of this cycle. This morphology of the corona and heliosphere differs from the one observed during the previous solar minimum when coronal streamers were confined to low heliolatitudes and the heliospheric current sheet was nearly flat. Interestingly, the polar magnetic fields observed at the solar photosphere during the present minimum are about 40% weaker than during the previous minimum. We use a potential field model to test if the weaker polar fields (and associated weaker dipole moment) can explain the differences observed in the corona and heliosphere during the past two minima. [ABSTRACT FROM AUTHOR]