Alpine climate during the Holocene: a comparison between records of glaciers, lake sediments and solar activity

2011 ◽  
Vol 26 (7) ◽  
pp. 703-713 ◽  
Author(s):  
Samuel U. Nussbaumer ◽  
Friedhelm Steinhilber ◽  
Mathias Trachsel ◽  
Petra Breitenmoser ◽  
Jürg Beer ◽  
...  
Keyword(s):  
Solar Activity ◽  
Lake Sediments ◽  
The Holocene

scholarly journals A reconstruction of radiocarbon production and total solar irradiance from the Holocene <sup>14</sup>C and CO<sub>2</sub> records: implications of data and model uncertainties

2013 ◽  
Vol 9 (4) ◽  
pp. 1879-1909 ◽  
Author(s):  
R. Roth ◽  
F. Joos
Keyword(s):  
Solar Activity ◽  
Solar Irradiance ◽  
Surface Air Temperature ◽  
Total Solar Irradiance ◽  
Production Model ◽  
High Solar Activity ◽  
Solar Modulation ◽  
Time Lags ◽  
Instrumental Data ◽  
The Holocene

Abstract. Radiocarbon production, solar activity, total solar irradiance (TSI) and solar-induced climate change are reconstructed for the Holocene (10 to 0 kyr BP), and TSI is predicted for the next centuries. The IntCal09/SHCal04 radiocarbon and ice core CO2 records, reconstructions of the geomagnetic dipole, and instrumental data of solar activity are applied in the Bern3D-LPJ, a fully featured Earth system model of intermediate complexity including a 3-D dynamic ocean, ocean sediments, and a dynamic vegetation model, and in formulations linking radiocarbon production, the solar modulation potential, and TSI. Uncertainties are assessed using Monte Carlo simulations and bounding scenarios. Transient climate simulations span the past 21 thousand years, thereby considering the time lags and uncertainties associated with the last glacial termination. Our carbon-cycle-based modern estimate of radiocarbon production of 1.7 atoms cm−2 s−1 is lower than previously reported for the cosmogenic nuclide production model by Masarik and Beer (2009) and is more in-line with Kovaltsov et al. (2012). In contrast to earlier studies, periods of high solar activity were quite common not only in recent millennia, but throughout the Holocene. Notable deviations compared to earlier reconstructions are also found on decadal to centennial timescales. We show that earlier Holocene reconstructions, not accounting for the interhemispheric gradients in radiocarbon, are biased low. Solar activity is during 28% of the time higher than the modern average (650 MeV), but the absolute values remain weakly constrained due to uncertainties in the normalisation of the solar modulation to instrumental data. A recently published solar activity–TSI relationship yields small changes in Holocene TSI of the order of 1 W m−2 with a Maunder Minimum irradiance reduction of 0.85 ± 0.16 W m−2. Related solar-induced variations in global mean surface air temperature are simulated to be within 0.1 K. Autoregressive modelling suggests a declining trend of solar activity in the 21st century towards average Holocene conditions.

scholarly journals The Solar Activity during the Holocene: Amplitude Variations of the Quasy-century and Quasi-two-century Solar Cycles

2004 ◽  
Vol 2004 (IAUS223) ◽  
pp. 705-706 ◽  
Author(s):  
Boris Komitov ◽  
Boncho Bonev ◽  
Kaloyan Penev ◽  
Stephano Sello
Keyword(s):  
Solar Activity ◽  
Solar Cycles ◽  
The Holocene

scholarly journals Solar activity during the Holocene: the Hallstatt cycle and its consequence for grand minima and maxima

2016 ◽  
Vol 587 ◽  
pp. A150 ◽  
Author(s):  
I. G. Usoskin ◽  
Y. Gallet ◽  
F. Lopes ◽  
G. A. Kovaltsov ◽  
G. Hulot
Keyword(s):  
Solar Activity ◽  
The Holocene ◽  
Grand Minima

scholarly journals A late Quaternary record of eolian silt deposition in a maar lake, St. Michael Island, western Alaska

2003 ◽  
Vol 60 (1) ◽  
pp. 110-122 ◽  
Author(s):  
Daniel R. Muhs ◽  
Thomas A. Ager ◽  
Josh Been ◽  
J. Platt Bradbury ◽  
Walter E. Dean
Keyword(s):  
Lake Sediments ◽  
Late Quaternary ◽  
Geochemical Data ◽  
Unexpected Finding ◽  
The Holocene ◽  
Tundra Vegetation ◽  
Shrub Tundra ◽  
Loess Deposition ◽  
Maar Lake ◽  
Glacial Time

AbstractRecent stratigraphic studies in central Alaska have yielded the unexpected finding that there is little evidence for full-glacial (late Wisconsin) loess deposition. Because the loess record of western Alaska is poorly exposed and not well known, we analyzed a core from Zagoskin Lake, a maar lake on St. Michael Island, to determine if a full-glacial eolian record could be found in that region. Particle size and geochemical data indicate that the mineral fraction of the lake sediments is not derived from the local basalt and is probably eolian. Silt deposition took place from at least the latter part of the mid-Wisconsin interstadial period through the Holocene, based on radiocarbon dating. Based on the locations of likely loess sources, eolian silt in western Alaska was probably deflated by northeasterly winds from glaciofluvial sediments. If last-glacial winds that deposited loess were indeed from the northeast, this reconstruction is in conflict with a model-derived reconstruction of paleowinds in Alaska. Mass accumulation rates in Zagoskin Lake were higher during the Pleistocene than during the Holocene. In addition, more eolian sediment is recorded in the lake sediments than as loess on the adjacent landscape. The thinner loess record on land may be due to the sparse, herb tundra vegetation that dominated the landscape in full-glacial time. Herb tundra would have been an inefficient loess trap compared to forest or even shrub tundra due to its low roughness height. The lack of abundant, full-glacial, eolian silt deposition in the loess stratigraphic record of central Alaska may be due, therefore, to a mimimal ability of the landscape to trap loess, rather than a lack of available eolian sediment.

Sign in / Sign up

Export Citation Format

Share Document