By Anthony Watts – Re-Blogged From WUWT
Something this big today would surely fry electrical grids, GPS, and communications. It may be bigger than the Carrington Solar event of 1859.
Scientists have found evidence of a huge blast of radiation from the Sun that hit Earth more than 2,000 years ago. The result has important implications for the present, because solar storms can disrupt modern technology.
The team found evidence in Greenland ice cores that the Earth was bombarded with solar proton particles in 660BC. The event was about 10 times more powerful than any since modern instrumental records began.
The Sun periodically releases huge blasts of charged particles and other radiation that can travel towards Earth.
The particular kind of solar emission recorded in the Greenland ice is known as a solar proton event (SPE). In the modern era, when these high-energy particles collide with Earth, they can knock out electronics in satellites we rely on for communications and services such as GPS.
The radiation may also pose a health risk for astronauts. And passengers and crew on commercial aircraft that fly at high altitudes and close to the poles, such as on transatlantic routes, could receive increased radiation doses – though this depends on many variables.
Other types of solar radiation events can trigger aurorae in the high atmosphere and shut down electrical grids.
Modern instrumental monitoring data extends back about 60 years. So finding an event in 660BC that’s an order of magnitude greater than anything seen in modern times suggests we haven’t appreciated how powerful such events can be.
660BC was the date, according to legend, when Japan’s first emperor – Jimmu – acceded to the throne. It was the time of the Iron Age in Europe and the Middle East – before the rise of the Roman Empire.
The researchers found evidence for the event in the form of radioactive isotopes (particular forms of an element) present in the Greenland ice. These were beryllium-10 and chlorine-36, which are regarded as being of cosmic origin.
Researchers have also identified two other large events from the past, which left evidence in both Greenland ice cores and tree rings. The signature researchers look for in tree rings is the isotope carbon-14.
Source: BBC Science
The research has been published in the journal Proceedings of the National Academy of Sciences (PNAS).
Multiradionuclide evidence for an extreme solar proton event around 2,610 B.P. (∼660 BC)
This study provides evidence of an enormous solar storm around 2,610 B.P. It is only the third such event reliably documented and is comparable with the strongest event detected at AD 774/775. The event of 2,610 years B.P. stands out because of its particular signature in the radionuclide data [i.e., carbon-14 (14C) data alone does not allow for an unequivocal detection of the event]. It illustrates that present efforts to find such events based solely on 14C data likely lead to an underestimated number of such potentially devastating events for our society. In addition to 14C data, high-resolution records of beryllium-10 and chlorine-36 are crucial for reliable estimates of the occurrence rate and the properties of past solar proton events.
Recently, it has been confirmed that extreme solar proton events can lead to significantly increased atmospheric production rates of cosmogenic radionuclides. Evidence of such events is recorded in annually resolved natural archives, such as tree rings [carbon-14 (14C)] and ice cores [beryllium-10 (10Be), chlorine-36 (36Cl)]. Here, we show evidence for an extreme solar event around 2,610 years B.P. (∼660 BC) based on high-resolution 10Be data from two Greenland ice cores. Our conclusions are supported by modeled 14C production rates for the same period. Using existing 36Cl ice core data in conjunction with 10Be, we further show that this solar event was characterized by a very hard energy spectrum. These results indicate that the 2,610-years B.P. event was an order of magnitude stronger than any solar event recorded during the instrumental period and comparable with the solar proton event of AD 774/775, the largest solar event known to date. The results illustrate the importance of multiple ice core radionuclide measurements for the reliable identification of short-term production rate increases and the assessment of their origins.
Multiradionuclide measurements for the 2,610-y B.P. (∼660 BC) event. (A) Time series for the newly measured NGRIP 10Be concentration (red curve, left axis) with corresponding measurement error margins and estimated natural baseline (dashed red line). Baseline concentration for 10Be is calculated as the average 10Be concentration for the measured period excluding the three peak values that span about 2.3 y. The red envelope represents the 10Be production range attributable to a solar modulation Φ varying between 500 and 1,200 MeV, which corresponds to a typical modern 11-y cycle (36). This estimate assumes that 10Be variations in Greenland ice cores vary proportionally to the global average 10Be production rate changes as supported by 10Be–14C comparison studies (29). NGRIP 10Be concentration measurements have been overlaid on the modeled 14C production rate inferred from the data shown in Fig. 1 (gray curve, right axis) with 1σ uncertainties (gray error bars). The 14C production rate is normalized to preindustrial absolute production rates. (B) Time series for 10Be (red curve, left axis) (ref. 26 and this study) and 36Cl concentrations measured in the GRIP ice core (blue curve, right axis) (21), with associated measurement errors (1σ) and calculated baseline concentration for 10Be and 36Cl (dashed blue line). Red and blue envelopes are as per A but considering the data’s lower resolution for 10Be and 36Cl, respectively. All ice core data are plotted on the timescale according to ref. 29. Please note that the timescale in A is stretched as indicated by the lines between the panels.