15 research outputs found

    Origins of the Ambient Solar Wind: Implications for Space Weather

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    The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal heating and the acceleration of the ambient solar wind. We also discuss where the community stands in its ability to forecast how variations in the solar wind (i.e., fast and slow wind streams) impact the Earth. Although the last few decades have seen significant progress in observations and modeling, we still do not have a complete understanding of the relevant physical processes, nor do we have a quantitatively precise census of which coronal structures contribute to specific types of solar wind. Fast streams are known to be connected to the central regions of large coronal holes. Slow streams, however, appear to come from a wide range of sources, including streamers, pseudostreamers, coronal loops, active regions, and coronal hole boundaries. Complicating our understanding even more is the fact that processes such as turbulence, stream-stream interactions, and Coulomb collisions can make it difficult to unambiguously map a parcel measured at 1 AU back down to its coronal source. We also review recent progress -- in theoretical modeling, observational data analysis, and forecasting techniques that sit at the interface between data and theory -- that gives us hope that the above problems are indeed solvable.Comment: Accepted for publication in Space Science Reviews. Special issue connected with a 2016 ISSI workshop on "The Scientific Foundations of Space Weather." 44 pages, 9 figure

    Blood, timber, and the state in West Kalimantan, Indonesia

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    West Kalimantan (West Borneo) has a history of violent communal conflict.1 It also has extensive forests that have been looted for decades. The argument will be that these two are linked, but not by the grievances of the forest dwellers. Except in its first few days, the two main episodes of 1997 and 1999 were not driven mainly by grievances among marginal groups. Rather, explanations based on the ‘resource curse’ carry more weight. These focus attention on the contested nature of the state, rather than on rebellious activities of marginal groups. When state institutions were thrown into disarray by the sudden resignation of President Suharto in 1998, Dayak militants already close to state power rewrote the rules of local politics by demonstratively ‘cleansing’ certain areas of an unpopular immigrant minority. This theatrical manoeuvre impressed political rivals sufficiently to allow Dayaks to gain control over several timber-rich districts, which had a thriving black economy. Malays later imitated these techniques to stem the tide
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