Remote Magnetic Helicity Caculation System (RMHCS)
The magnetic environment of Earth is strongly influenced by the Sun and its activity, and it is nowadays recognized to be a highly interlinked system whose variability is know as space weather. The ability to forecast its evolution relies on our understanding of the physical processes that take place on the Sun, such as flares and coronal mass ejections (CMEs). In recent years, magnetic helicity has become an attractive, seemingly viable, and promising candidate for the general description and interpretation of many solar events relevant to space weather. In particular, the conservation properties of helicity under typical solar conditions supports its use as a tracer during different phases of the life of twisted, tangled magnetic structures, from their formation below the photosphere, to their stability properties in the coronal atmosphere, to their propagation in interplanetary space as ICME. Such a powerful description requires a deep understanding of the properties of magnetic helicity, and accurate methods for its estimation. (ISSI TEAM PROPOSAL 2014)
Fig 1. Structure of magnetic structure with helicity (Berger 1999)
This website is to introduce how to use the Remote Magnetic Helicity Caculation System (RMHCS). We setup a web server to response and calculate the relative magnetic helicity of the data from the users and send the result back. You can also use email to receive the result.
IDL6.4+ or Free GNU Data Language
Java 6+ http://www.java.com/
Please fill informaiton and download RMHCS IDL CODE
1. Upload data you need to set the path of this procedure in this procedure: SETENV, 'helicity_path=THEPROCEDUREPATH' . If name is not set. the system time will be used (million seconds)
2. Query a calculation to the server. You can set your email address for receive the waring when the calculation is ready, The name and email are all string format.
3. check the status of sending job, RH is the helicity, error is the energy errors which reflects the helicity results whether is OK.
4. rh3d_remote function included all the process above:
The data is in the rectangular cartesian coordinate system.
The maximul size of data is 256x256x256. If too large, the sending job will be cancelled after 3 hours. If the condition of divergence free is good enough, the data can be resize to small volume to obtain the very similar results.
The failed with unknown reason data will be deleted from server after 7 days.
This study is supported by KJCX2-EWT07 of Knowledge Innovation Program of The Chinese Academy of Sciences and Grants 11078012, 11178016, 11173033, 11125314, 10733020, 10921303, 41174153, 11103038 and 10673016 of National Natural Science Foundation of China, and 2011CB811400 of National Basic Research Program of China and KLSA201211, KLSA201227 and KLSA201413 of the Collaborating Research Program of National Astronomical Observatories, Chinese Academy of Sciences and the Young Reseracher Grant of National Astronomical Observatories, Chinese Academy of Sciences.