Climate variability in the northern and southern Altai Mountains during the past 50 years

Fifteen proxy records of summer temperature in Fennoscandia, Northern Europe and in Yamal and Taymir Peninsulas (Western Siberia) were analyzed for the AD 1700–2000 period. Century-long (70–100 year) and quasi bi-decadal periodicities were found from proxy records representing different parts of Fennoscandia. Decadal variation was revealed in a smaller number of records. Statistically significant correlations were revealed between the timescale-dependent components of temperature variability and solar cycles of Schwabe (~11 year), Hale (~22 year), and Gleissberg (сentury-long) as recorded in solar activity data. Combining the results from our correlation analysis with the evidence of solar-climatic linkages over the Northern Fennoscandia obtained over the past 20 years suggest that there are two possible explanations for the obtained solar-proxy relations: (a) the Sun’s activity actually influences the climate variability in Northern Fennoscandia and in some regions of the Northern Hemisphere albeit the mechanism of such solar-climatic linkages are yet to be detailed; (b) the revealed solar-type periodicities result from natural instability of climate system and, in such a case, the correlations may appear purely by chance. Multiple lines of evidence support the first assumption but we note that the second one cannot be yet rejected. Guidelines for further research to elucidate this question are proposed including the Fisher’s combined probability test in the presence of solar signal in multiple proxy records.

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A chrysophyte-based quantitative reconstruction of winter severity from varved lake sediments in NE Poland during the past millennium and its relationship to natural climate variability

Quaternary Science Reviews ◽

10.1016/j.quascirev.2015.05.029 ◽

2015 ◽

Vol 122 ◽

pp. 74-88 ◽

Cited By ~ 9

Author(s):

I. Hernández-Almeida ◽

M. Grosjean ◽

R. Przybylak ◽

W. Tylmann

Keyword(s):

Climate Variability ◽

Lake Sediments ◽

Natural Climate Variability ◽

Quantitative Reconstruction ◽

The Past ◽

Ne Poland ◽

Varved Lake Sediments ◽

Natural Climate ◽

Past Millennium ◽

Winter Severity

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Mid-Pleistocene transition in glacial cycles explained by declining CO2and regolith removal

Science Advances ◽

10.1126/sciadv.aav7337 ◽

2019 ◽

Vol 5 (4) ◽

pp. eaav7337 ◽

Cited By ~ 44

Author(s):

M. Willeit ◽

A. Ganopolski ◽

R. Calov ◽

V. Brovkin

Keyword(s):

Climate Variability ◽

Carbon Cycle ◽

Northern Hemisphere ◽

Seasonal Variations ◽

Ice Sheets ◽

Glacial Cycles ◽

Solar Insolation ◽

The Past ◽

Transient Simulations

Variations in Earth’s orbit pace the glacial-interglacial cycles of the Quaternary, but the mechanisms that transform regional and seasonal variations in solar insolation into glacial-interglacial cycles are still elusive. Here, we present transient simulations of coevolution of climate, ice sheets, and carbon cycle over the past 3 million years. We show that a gradual lowering of atmospheric CO2and regolith removal are essential to reproduce the evolution of climate variability over the Quaternary. The long-term CO2decrease leads to the initiation of Northern Hemisphere glaciation and an increase in the amplitude of glacial-interglacial variations, while the combined effect of CO2decline and regolith removal controls the timing of the transition from a 41,000- to 100,000-year world. Our results suggest that the current CO2concentration is unprecedented over the past 3 million years and that global temperature never exceeded the preindustrial value by more than 2°C during the Quaternary.

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