以下の英文の和訳をお願いします。
Although the magnitude of the variations of carbon-14 is strongly attenuated through the carbon cycle after being produced by the GCRs in the atmosphere (Siegenthaler and Beer, 1988), carbon-14 in tree-rings preserve the information on the variations in solar cycles and the magnetic dipole polarity of the sun. Therefore, the variability of the “11-year” solar cycle in association with the century-scale variations of solar activity can be monitored to asses its influence on climate.
The lengths of sunspot periods have been modulated by a few years since the 11-year sunspot cycle was firstly found by Schwabe (1843). The maximum range observed so far is ~ 9 to ~ 14 years, but most of the cycles fit in ~ 10–12 years with the overall average being 11 years. However, we have previously found a change in average cycle length during the Maunder Minimum ((Miyahara et al., 2004); see Supplementary Fig. S1). The sunspots were scarce through 1645–1715 AD due to the anomalous weakening of the magnetic activity at this time, yet the carbon-14 abundances show the appearance of significant cyclic changes in magnetic activity. The average length of the cycles through the 70 years was about 14 years with the 28-year period of magnetic polarity reversals. The relationship between the cycle length of the “11-year” variation in sunspots and its magnitude has been investigated in several papers (Clough, 1905, Solanki et al., 2002 and Rogers et al., 2006). A consistent feature is the inverse correlation between cycle amplitudes and cycle lengths that maybe related to the change of the meridional flows inside the convection zone of the sun (Hathaway et al., 2003).
お礼
回答ありがとうござます。 ここには記していない文脈から判断すると、おそらくuncompleted job spellは契約期間が満了していなということではなく、アメリカで一つの仕事に就いている平均的な期間が約7.5年であり、この平均に満たない期間のことを意味しているように思います。 でも、こうした解釈をするのにad-astraさんの回答が大きなヒントになりました。本当に助かりました。