Interpreting ¹⁰Be changes during the Maunder Minimum

Abstract

Beryllium‐10 archives are important resources for understanding how solar activity may have varied in the past. Climate simulations using the Goddard Institute for Space Studies ModelE general circulation model are used to calibrate the impacts of production changes, solar forcings, and volcanic aerosol forcing on 10Be concentration during periods such as the Maunder Minimum (1645–1715 A.D.). We find that for the preindustrial period, production‐related 10Be changes are the dominant signal in snow concentration, and that the effects of both solar and volcanic forcings on climate are relatively minor. Ambiguities in determining the observed changes in 10Be snow concentration during the Maunder Minimum complicate the process of estimating changes in the solar modulation strength during that time. Given those limitations, we estimate that the average value of the solar modulation parameter ϕ was between 280 and 395 MeV over the course of the Maunder Minimum, and was approximately 142 MeV during the years of peak 10Be concentration as recorded in the Dye 3 and South Pole ice core records.

What Voyager cosmic ray data in the outer heliosphere tells us about 10Be production in the Earth's polar atmosphere in the recent past

“…Indeed the role of climatic effects has been increasingly recognized following earlier suggestions by Raisbeck et al [1981] and Lal [1987]. Pedro et al [2006], Field et al [2006], and more recently Heikkila et al [2008] and Field et al [2009], have evaluated these climatic effects in increasing detail with Field et al [2009], particularly noting that the modulation estimates of McCracken et al [2004], near the Maunder minimum would be significantly modified by climatic effects, in line with our own conclusions above.…”

“…One of the first uses of this 10 Be variability was to trace the 11 year cycle of solar activity covering several hundred years [ Beer et al , 1990]. These studies have all assumed that the production rate of 10 Be in the Earth's polar atmosphere is directly (linearly) related to the measured concentration [e.g., McCracken et al , 2004] and this assumption is sometimes made even though many studies have indicated the importance of climatic effects on both a short‐term and long‐term scale [e.g., Raisbeck et al , 1981; Lal , 1987; Pedro et al , 2006; Field et al , 2006; Heikkila et al , 2008; Field et al , 2009].…”

Climate forcing reconstructions for use in PMIP simulations of the last millennium (v1.0)

“…Second, the factors that affect open solar magnetic field are uncertainly linked to solar irradiance, though much work is being done to elucidate the connection (Wang et al, 2005;Krivova et al, 2007;Vieira et al, 2010). Additionally, the relationships of the cosmogenic archives to global mean production levels may be themselves somewhat affected by climate (Field et al, 2009;Heikkilä et al, 2008). Nonetheless, there is sufficient qualitative overlap of the different proxies where they are available to combine them quantitatively to produce a homogeneous record of solar activity back through time (Vonmoos et al, 2006;Usoskin et al, 2009).…”

Beryllium-10 transport to Antarctica: Results from seasonally resolved observations and modeling

“…From a modeling perspective, simulation of 10 Be requires a three‐dimensional model of the atmosphere, coupled with an aerosol module describing the production, transport and deposition processes of atmospheric particles. Both the GISS ModelE [ Schmidt et al , 2006] and the ECHAM5‐HAM GCMs [ Roeckner , 2003] have been used to simulate 10 Be deposition to the ice sheets [ Heikkilä et al , 2008c, 2009; Field et al , 2006, 2009; Field and Schmidt , 2009]. To date, because of the lack of highly resolved records, it has not been possible to test GCM performance against seasonal variations in 10 Be concentrations in Antarctic ice.…”