Cosmic rays data from Mawson, Antarctica is available from 28 June 2004.
Cosmic rays consist mainly of protons. They can originate from galactic cosmic radiation or from the Sun. Cosmic rays are observed indirectly by a device known as a neutron monitor. When cosmic ray particles enter the Earth's atmosphere they interact with the nuclei of the air molecules to produce secondary radiation. This consists of pions (which decay to muons) and a shower of protons and neutrons. The neutrons predominate in this secondary radiation because the protons, being charged are more easily attenuated in subsequent travel. The cosmic ray detector actual detects these secondary neutrons and as a consequence is referred to as a neutron monitor.
Neutron Monitor Data from Mawson, Antarctica
Data is transferred at 5 minute intervals, 1 record per minute. For slow ground level event detection (increase in count rate) and Forbush decrease (decrease in count rate) hourly averages of the minute data are used. Alert thresholds (above and below) have been set at 4 times the standard deviation obtained over a 48 hour period. In addition Forbush decrease events must be at least 3% for a SWS Forbush Decrease alert to be issued. The threshold shown in the plots are the 5 times standard deviation threshold. The requirement of at least a 3% decrease is necessary for when the cosmic ray data exhibits very little variation, bringing the 4 times standard variation threshold potentially very close in counts to small data count fluctuations, increasing the risk of false alarms being produced.
For fast ground level events the minute data is used with a increase perentage threshold of 10%.
To try and minimize GLE false alarms the GOES solar X-ray flux must also be greater than M5 at the time of detection of the GLE.
The above thresholds are experimental and may need to be adjusted with experience.
The data displayed below is provided by the Australian Antarctic program in near real time. A neutron monitor located in Antarctica has no geomagnetic (lower) cutoff energy (although there is atmospheric cutoff energy), and thus provides the most sensitive indication of cosmic radiation of any sensor located on the Earth's surface.
Version:2.2.3
Cosmic rays data from Mawson, Antarctica is available from 28 June 2004.
Cosmic rays consist mainly of protons. They can originate from galactic cosmic radiation or from the Sun. Cosmic rays are observed indirectly by a device known as a neutron monitor. When cosmic ray particles enter the Earth's atmosphere they interact with the nuclei of the air molecules to produce secondary radiation. This consists of pions (which decay to muons) and a shower of protons and neutrons. The neutrons predominate in this secondary radiation because the protons, being charged are more easily attenuated in subsequent travel. The cosmic ray detector actual detects these secondary neutrons and as a consequence is referred to as a neutron monitor.
Neutron Monitor Data from Mawson, Antarctica
Data is transferred at 5 minute intervals, 1 record per minute. For slow ground level event detection (increase in count rate) and Forbush decrease (decrease in count rate) hourly averages of the minute data are used. Alert thresholds (above and below) have been set at 4 times the standard deviation obtained over a 48 hour period. In addition Forbush decrease events must be at least 3% for a SWS Forbush Decrease alert to be issued. The threshold shown in the plots are the 5 times standard deviation threshold. The requirement of at least a 3% decrease is necessary for when the cosmic ray data exhibits very little variation, bringing the 4 times standard variation threshold potentially very close in counts to small data count fluctuations, increasing the risk of false alarms being produced.
For fast ground level events the minute data is used with a increase perentage threshold of 10%.
To try and minimize GLE false alarms the GOES solar X-ray flux must also be greater than M5 at the time of detection of the GLE.
The above thresholds are experimental and may need to be adjusted with experience.
The data displayed below is provided by the Australian Antarctic program in near real time. A neutron monitor located in Antarctica has no geomagnetic (lower) cutoff energy (although there is atmospheric cutoff energy), and thus provides the most sensitive indication of cosmic radiation of any sensor located on the Earth's surface.
| Role | Person | StartDate | StopDate | Note | |
|---|---|---|---|---|---|
| 1. | GeneralContact | spase://ASWS/Person/Kehe.Wang | |||
| 2. | MetadataContact | spase://SMWG/Person/Lee.Frost.Bargatze |