Cosmic Rays in the Heliosphere

Leading scientists in the field assess the current state of our understanding of the spatial and temporal variations of galactic and anomalous cosmic rays in the Heliosphere, and their relation to effects of the Sun. The main objective is to understand the spatial and temporal variation of galactic and anomalous cosmic rays in the light of recent observations, theory and modeling by identifying the key mechanism(s) of cosmic ray modulation and how changes on the Sun relate to changes in the observed characteristics of cosmic rays in the Heliosphere; examining the current long-lasting solar minimum and understand its implications for solar-cycle variations and long-term variations; and interpreting the long-term variations of cosmogenic radionuclides in terms of solar variability and climate change on Earth. This volume is aimed at graduate students active in the fields of solar physics, space science, and cosmic ray physics. Originally published in Space Science Reviews journal, Vol. 176/1-4, 2013. Presents a comprehensive synopsis of the current state of cosmic rays, their modulation and their effects in the Earth’s atmosphere. Leading scientists in the field assess the current state of our understanding of the spatial and temporal variations of galactic and anomalous cosmic rays in the Heliosphere, and their relation to effects of the Sun. The main objective is to understand the spatial and temporal variation of galactic and anomalous cosmic rays in the light of recent observations, theory and modeling by identifying the key mechanism(s) of cosmic ray modulation and how changes on the Sun relate to changes in the observed characteristics of cosmic rays in the Heliosphere; examining the current long-lasting solar minimum and understand its implications for solar-cycle variations and long-term variations; and interpreting the long-term variations of cosmogenic radionuclides in terms of solar variability and climate change on Earth. This volume is aimed at graduate students active in the fields of solar physics, space science, and cosmic ray physics. Originally published in Space Science Reviews journal, Vol. 176/1-4, 2013.

We have been fortunate to have an array of spacecraft - unprecedented in the history of space exploration and unlikely to be repeated for generations - to provide comprehensive measurements of cosmic rays throughout the heliosphere. In every scientific discipline there are milestones - periods of significant accom­ plishment when it is appropriate to pause and summarize the state of the field. Such is the case for the study of the behavior of cosmic rays in the heliosphere. We are just passing through solar minimum conditions, when the heliosphere has a well-ordered and relatively simple configuration. We have been fortunate to have an array of spacecraft - unprecedented in the history of space exploration and unlikely to be repeated for generations - to provide comprehensive measurements of cosmic rays throughout the heliosphere. Ulysses has completed its historic first exploration of the heliosphere at high heliographic latitudes. Pioneer and Voyager have been exploring the outer heliosphere. The durable IMP-8 and now the WIND spacecraft have provided detailed baseline measurements at Earth. Concurrently, there has been a steady improvement in theoretical understanding of cosmic ray behavior through the use of ever more sophisticated numerical models. This milestone in cosmic ray studies was celebrated with a Workshop on Cos­ mic Rays in the Heliosphere which was convened by L. A. Fisk, J. R. Jokipii.