Cosmogenic radiocarbon as a means of studying solar activity in the past     

G. E. Kocharov  M. G. Ogurtsov  S. L. Tsereteli 《Astronomy Reports》2003,47(12):1054-1062

A series of yearly data on the concentration of radioactive carbon ¹⁴C in tree rings measured at the Tbilisi State University in 1983–1986 and covering the time interval 1600–1940 is statistically analyzed. We find evidence for a 22-year cyclicity in the intensity of Galactic cosmic rays (GCRs) during the Maunder minimum of the solar activity (1645–1715), testifying that the solar dynamo mechanism continued to operate during this epoch. Variations of Δ¹⁴C on timescales of tens and hundreds of years correlate well with the corresponding variations of the GCR intensity and solar activity, making radiocarbon a reliable source of information on long-timescale variations of solar activity in the past. Short-timescale (<30 years) fluctuations of Δ¹⁴C may be appreciably distorted by time variations not associated directly with solar activity; probable origins of this distortion are discussed.  相似文献   

On the link between northern fennoscandian climate and length of the quasi-eleven-year cycle in galactic cosmic-ray flux     

Ogurtsov  M.G.  Jungner  H.  Kocharov  G.E.  Lindholm  M.  Eronen  M.  Nagovitsyn  Yu.A. 《Solar physics》2003,218(1-2):345-357

Bidecadal fluctuations in terrestrial climate were analyzed. It was shown that this variability might arise if Earth's climate reacts to galactic cosmic-ray intensity, integrated over its full quasi-11-year cycle. It was further shown that this integral effect should also lead to an effective link between climate and the duration of the quasi-11-year cycle in cosmic ray flux. That, in turn, must result in appearance of some connection between climate and the length of the solar cycle, which is currently a topic of active debate. Analyses of temperature proxies, obtained for northern Fennoscandia, confirmed the connection of the climate in this region and the length of the cycle in galactic cosmic-ray intensity. Decadal and bidecadal variability of integrated cosmic-ray flux was quantitatively estimated.  相似文献   

On the Quasi-Five-Year Variation of Nitrate Abundance in Polar ice and Solar Flare Activity in the Past     

Kocharov  G.E.  Ogurtsov  M.G.  Dreschhoff  G.A.M. 《Solar physics》1999,188(1):187-190

The quasi-five-year variation in the abundance of nitrate in Central Greenland ice is revealed. Probable origin of the variation is the connection of solar proton events with the period of declining solar activity. Such a connection exists during more than 200 years and appears to be a fundamental property of solar activity.  相似文献   

Reconstruction of the Wolf Numbers Based on Radiocarbon Data from the Early 11th Century until the Middle of the 19th Century with Respect to Climate Changes     

Kuleshova  A. I.  Dergachev  V. A.  Kudryavtsev  I. V.  Nagovitsyn  Yu. A.  Ogurtsov  M. G. 《Geomagnetism and Aeronomy》2018,58(8):1097-1102

Geomagnetism and Aeronomy - The results of the reconstruction of Wolf numbers from the 11th century until the middle of the 19th century A.D. based on radiocarbon data are presented. This time span...  相似文献   

Reconstruction of the Production Rate of Cosmogenic 14C in the Earth’s Atmosphere for 17 000–5000 BC     

Kudryavtsev  I. V.  Volobuev  D. M.  Dergachev  V. A.  Nagovitsyn  Yu. A.  Ogurtsov  M. G. 《Geomagnetism and Aeronomy》2018,58(7):925-929

Geomagnetism and Aeronomy - Carbon isotope 14С is produced in the Earth’s atmosphere by energetic cosmic-ray (CR) particles. The data on its atmospheric abundance are used to...  相似文献   

Halistatt Cycle Subarctic Fennoscandian Temperature and Its Possible Link with Solar Activity     

Ogurtsov  M. G.  Helama  S. 《Geomagnetism and Aeronomy》2018,58(8):1029-1036

Geomagnetism and Aeronomy - Reconstruction of summer temperature at subarctic Fennoscandia (68°–70° N, 20°–30° E), based on tree-ring data, was compared with three...  相似文献   

Solar System Collisions with Dense Interstellar Gas Clouds and Radiocarbon Traces of Periods with “Abnormally Low” Solar Modulation of Cosmic Rays     

Vasil’ev  G. I.  Konstantinov  A. N.  Kudryavtsev  I. V.  Ogurtsov  M. G.  Ostryakov  V. M.  Pavlov  A. K.  Frolov  D. A. 《Geomagnetism and Aeronomy》2019,59(8):1075-1080

Geomagnetism and Aeronomy - The causes of a sharp increase in the radiocarbon content in the Earth’s atmosphere for periods with abnormally low solar modulation of galactic cosmic rays (GCRs)...  相似文献   

Reconstructions of the heliospheric modulation potential and Wolf numbers based on the content of the <Superscript>14</Superscript>C isotope in tree rings during the Maunder and Spörer minimums     

I. V. Kudryavtsev  V. A. Dergachev  A. I. Kuleshova  Yu. A. Nagovitsyn  M. G. Ogurtsov 《Geomagnetism and Aeronomy》2016,56(8):998-1005

Data on variations in the content of the 14C cosmogenic isotope in tree rings and the Earth’s atmosphere (Δ¹⁴C) make it possible to study the behavior of solar activity (SA) in previous centuries and millenniums. The latter is related to the fact that SA temporal variations result in a change in the IMF (Interplanetary Magnetic Field) parameters and, as a consequence, in the galactic cosmic ray (GCR) flux, under the action of which the ¹⁴C isotope is produced in the Earth’s atmosphere. This makes it possible to study SA history based on data on the ¹⁴C isotope content in tree rings. However, in this case we have several difficulties related to climate change. Climate changes result in carbon redistribution between natural reservoirs, which is reflected in radiocarbon data and results in solar signal distortion. The effect of variations in the global temperature and carbon dioxide concentration on the reconstruction of the heliospheric modulation potential and Wolf numbers from the late 14th century to the early 19th century is considered. It has been shown that the radiocarbon data do not make it possible to conclude that SA during the Maunder minimum was extremely low as compared to SA during the Dalton minimum.  相似文献   

Cloud anomalies at midlatitudes of the Northern and Southern Hemispheres: Connection with atmospheric dynamics and variations in cosmic rays     

Veretenenko  S. V.  Ogurtsov  M. G. 《Geomagnetism and Aeronomy》2016,56(8):1110-1117

Geomagnetism and Aeronomy - Long-term correlations between the state of low clouds and variations in the flux of galactic cosmic rays (GCRs) were studied. It has been shown that the links between...  相似文献   

Possible contribution of surface temperature variation to the radiocarbon concentration in the Earth’s atmosphere     

M. G. Ogurtsov  V. A. Dergachev  I. V. Koudriavtsev  Yu. A. Nagovitsyn  V. M. Ostryakov 《Geomagnetism and Aeronomy》2015,55(7):931-937

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