scholarly journals Multi-millennial-scale solar activity and its influences on continental tropical climate: empirical evidence of recurrent cosmic and terrestrial patterns

2015 ◽  
Vol 6 (2) ◽  
pp. 1237-1260
Author(s):  
J. Sánchez-Sesma
Keyword(s):  
Solar Activity ◽  
Empirical Evidence ◽  
Tropical Climate ◽  
Solar Oscillations ◽  
Empirical Modelling ◽  
Last Glacial ◽  
The Past ◽  
Astronomical Forcing ◽  
The Last Glacial ◽  
Millennial Scale

Abstract. Solar activity (SA) oscillations over the past millennia are analyzed and extrapolated based on reconstructed solar-related records. Here, simple recurrent models of SA signal are applied and tested. The consequent results strongly suggest: (a) the existence of multi-millennial (~ 9500 years) scale solar oscillations, and (b) their persistence, over at least the last glacial–interglacial cycle. This empirical modelling of solar recurrent oscillations has also provided a consequent multi-millennial-scale experimental forecast, suggesting a solar decreasing trend toward Grand (Super) Minimum conditions for the upcoming period, AD 2050–2250 (AD 3750–4450). Also, a recurrent linear influence of solar variation on continental tropical climate (CTC) has been assessed for the last 20 kyr, and extrapolated for the next centuries. Taking into account the importance of these estimated SA scenarios a comparison is made with other SA forecasts, and their possible associated astronomical forcing and influences on past and future CTC discussed.

scholarly journals Evidence of cosmic recurrent and lagged millennia-scale patterns and consequent forecasts: multi-scale responses of solar activity (SA) to planetary gravitational forcing (PGF)

2016 ◽  
Vol 7 (3) ◽  
pp. 583-595 ◽  
Author(s):  
Jorge Sánchez-Sesma
Keyword(s):  
Solar Activity ◽  
Empirical Modeling ◽  
Last Glacial ◽  
Multi Scale ◽  
The Past ◽  
Recurrent Patterns ◽  
The Last Glacial ◽  
Millennial Scale

Abstract. Solar activity (SA) oscillations over the past millennia are analyzed and extrapolated based on reconstructed solar-related records. Here, simple recurrent models of SA signal are applied and tested. The consequent results strongly suggest the following: (a) the existence of multi-millennial ( ∼ 9500-year) scale solar patterns linked with planetary gravitational forcing (PGF), and (b) their persistence, over at least the last glacial–interglacial cycle, but possibly since the Miocene (10.5 Myr ago). This empirical modeling of solar recurrent patterns has also provided a consequent multi-millennial-scale experimental forecast, suggesting a solar decreasing trend toward grand (super) minimum conditions for the upcoming period, AD 2050–2250 (AD 3750–4450). Taking into account the importance of these estimated SA scenarios, a comparison is made with other SA forecasts. In Appendixes A and B, we provide further verification, testing and analysis of solar recurrent patterns since geological eras, and their potential gravitational forcing.

Reconstructions of the past distribution of Testudo graeca mitochondrial lineages in the Middle East and Transcaucasia support multiple refugia since the Last Glacial Maximum

2021 ◽  
pp. 10-17
Author(s):  
Oguz Turkozan
Keyword(s):  
Middle East ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Testudo Graeca ◽  
Last Glacial ◽  
The Past ◽  
Precipitation Seasonality ◽  
Multiple Refugia ◽  
The Last Glacial Maximum ◽  
The Last Glacial

A cycle of glacial and interglacial periods in the Quaternary caused species’ ranges to expand and contract in response to climatic and environmental changes. During interglacial periods, many species expanded their distribution ranges from refugia into higher elevations and latitudes. In the present work, we projected the responses of the five lineages of Testudo graeca in the Middle East and Transcaucasia as the climate shifted from the Last Glacial Maximum (LGM, Mid – Holocene), to the present. Under the past LGM and Mid-Holocene bioclimatic conditions, models predicted relatively more suitable habitats for some of the lineages. The most significant bioclimatic variables in predicting the present and past potential distribution of clades are the precipitation of the warmest quarter for T. g. armeniaca (95.8 %), precipitation seasonality for T. g. buxtoni (85.0 %), minimum temperature of the coldest month for T. g. ibera (75.4 %), precipitation of the coldest quarter for T. g. terrestris (34.1 %), and the mean temperature of the driest quarter for T. g. zarudyni (88.8 %). Since the LGM, we hypothesise that the ranges of lineages have either expanded (T. g. ibera), contracted (T. g. zarudnyi) or remained stable (T. g. terrestris), and for other two taxa (T. g. armeniaca and T. g. buxtoni) the pattern remains unclear. Our analysis predicts multiple refugia for Testudo during the LGM and supports previous hypotheses about high lineage richness in Anatolia resulting from secondary contact.

scholarly journals <i>δ</i><sup>13</sup>C decreases in the upper western South Atlantic during Heinrich Stadials 3 and 2

2017 ◽  
Vol 13 (4) ◽  
pp. 345-358 ◽  
Author(s):  
Marília C. Campos ◽  
Cristiano M. Chiessi ◽  
Ines Voigt ◽  
Alberto R. Piola ◽  
Henning Kuhnert ◽  
...  
Keyword(s):  
Climate Change ◽  
South Atlantic ◽  
Meridional Overturning Circulation ◽  
Glacial Period ◽  
Last Deglaciation ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Change Events ◽  
The Last Glacial ◽  
Millennial Scale

Abstract. Abrupt millennial-scale climate change events of the last deglaciation (i.e. Heinrich Stadial 1 and the Younger Dryas) were accompanied by marked increases in atmospheric CO2 (CO2atm) and decreases in its stable carbon isotopic ratios (δ13C), i.e. δ13CO2atm, presumably due to outgassing from the ocean. However, information on the preceding Heinrich Stadials during the last glacial period is scarce. Here we present δ13C records from two species of planktonic foraminifera from the western South Atlantic that reveal major decreases (up to 1 ‰) during Heinrich Stadials 3 and 2. These δ13C decreases are most likely related to millennial-scale periods of weakening of the Atlantic meridional overturning circulation and the consequent increase (decrease) in CO2atm (δ13CO2atm). We hypothesise two mechanisms that could account for the decreases observed in our records, namely strengthening of Southern Ocean deep-water ventilation and weakening of the biological pump. Additionally, we suggest that air–sea gas exchange could have contributed to the observed δ13C decreases. Together with other lines of evidence, our data are consistent with the hypothesis that the CO2 added to the atmosphere during abrupt millennial-scale climate change events of the last glacial period also originated in the ocean and reached the atmosphere by outgassing. The temporal evolution of δ13C during Heinrich Stadials 3 and 2 in our records is characterized by two relative minima separated by a relative maximum. This w structure is also found in North Atlantic and South American records, further suggesting that such a structure is a pervasive feature of Heinrich Stadial 2 and, possibly, also Heinrich Stadial 3.

scholarly journals Environmental variability in response to abrupt climatic change during the Last Glacial–Interglacial Transition (16–8 cal ka BP): evidence from Mainland, Orkney

2019 ◽  
Vol 56 (1) ◽  
pp. 30-46 ◽  
Author(s):  
Ashley M. Abrook ◽  
Ian P. Matthews ◽  
Alice M. Milner ◽  
Ian Candy ◽  
Adrian P. Palmer ◽  
...  
Keyword(s):  
Early Career ◽  
Early Holocene ◽  
Content Type ◽  
Last Glacial ◽  
Principal Curve ◽  
Link Type ◽  
Supplementary Material ◽  
Career Research ◽  
The Last Glacial ◽  
Millennial Scale

The Last Glacial–Interglacial Transition (LGIT) is a period of climatic complexity where millennial-scale climatic reorganization led to changes in ecosystems. Alongside millennial-scale changes, centennial-scale climatic events have been observed within records from Greenland and continental Europe. The effects of these abrupt events on landscapes and environments are difficult to discern at present. This, in part, relates to low temporal resolutions attained by many studies and the sensitivity of palaeoenvironmental proxies to abrupt change. We present a high-resolution palynological and charcoal study of Quoyloo Meadow, Orkney and use the Principal Curve statistical method to assist in revealing biostratigraphic change. The LGIT vegetation succession on Orkney is presented as open grassland and Empetrum heath during the Windermere Interstadial and early Holocene, and open grassland with Artemisia during the Loch Lomond Stadial. However, a further three phases of ecological change, characterized by expansions of open ground flora, are dated to 14.05–13.63, 10.94–10.8 and 10.2 cal ka BP. The timing of these changes is constrained by cryptotephra of known age. The paper concludes by comparing Quoyloo Meadow with Crudale Meadow, Orkney, and suggests that both Windermere Interstadial records are incomplete and that fire is an important landscape control during the early Holocene.Supplementary material: All raw data associated with this publication: raw pollen counts, charcoal data, Principal Curve and Rate of Change outputs and the age-model output are available at https://doi.org/10.6084/m9.figshare.c.4725269Thematic collection: This article is part of the ‘Early Career Research’ available at: https://www.lyellcollection.org/cc/SJG-early-career-research

Millennial‐scale environmental changes in the northwestern Japan Sea during the last glacial cycle

Boreas ◽  
2020 ◽  
Author(s):  
Tatiana A. Evstigneeva ◽  
Marina V. Cherepanova ◽  
Sergey A. Gorbarenko ◽  
Xuefa Shi ◽  
Alexander A. Bosin ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Japan Sea ◽  
Glacial Cycle ◽  
Last Glacial ◽  
The Last Glacial ◽  
Millennial Scale
Sign in / Sign up

Export Citation Format

Share Document