scholarly journals Quasi ~500-year Cycle Signals in Solar Activity

2018 ◽  
Vol 7 (1) ◽  
pp. 131
Author(s):  
Lihua Ma ◽  
Zhiqiang Yin ◽  
Yanben Han
Keyword(s):  
Solar Activity ◽  
Power Spectrum ◽  
Wavelet Power Spectrum ◽  
Geomagnetic Variations ◽  
The Past ◽  
Direct Observations ◽  
Periodic Signals ◽  
Activity Series

Direct observations of solar activity are available for the past four century, so some proxies reflecting solar activity such as 14C, 10Be and geomagnetic variations are used to reconstruct solar activity in the past. In this present paper, the authors use rectified wavelet power transform and time-averaged wavelet power spectrum to investigate long-term fluctuations of the reconstructed solar activity series. Results show obvious a quasi ~500-year cycle exists in the past solar activity. Three reconstructed solar activity series from 14C variations confirm the periodic signals.

scholarly journals Estimation of permafrost thawing rates in a sub-arctic catchment using recession flow analysis

2009 ◽  
Vol 13 (5) ◽  
pp. 595-604 ◽  
Author(s):  
S. W. Lyon ◽  
G. Destouni ◽  
R. Giesler ◽  
C. Humborg ◽  
M. Mörth ◽  
...  
Keyword(s):  
Average Rate ◽  
Flow Analysis ◽  
The Arctic ◽  
Northern Sweden ◽  
The Past ◽  
Direct Observations ◽  
Flow Pathways ◽  
Thawing Rate ◽  
Permafrost Thawing

Abstract. Permafrost thawing is likely to change the flow pathways taken by water as it moves through arctic and sub-arctic landscapes. The location and distribution of these pathways directly influence the carbon and other biogeochemical cycling in northern latitude catchments. While permafrost thawing due to climate change has been observed in the arctic and sub-arctic, direct observations of permafrost depth are difficult to perform at scales larger than a local scale. Using recession flow analysis, it may be possible to detect and estimate the rate of permafrost thawing based on a long-term streamflow record. We demonstrate the application of this approach to the sub-arctic Abiskojokken catchment in northern Sweden. Based on recession flow analysis, we estimate that permafrost in this catchment may be thawing at an average rate of about 0.9 cm/yr during the past 90 years. This estimated thawing rate is consistent with direct observations of permafrost thawing rates, ranging from 0.7 to 1.3 cm/yr over the past 30 years in the region.

scholarly journals Long-term solar activity and terrestrial connections. Part II: at the beckon of the sun?

1998 ◽  
Vol 16 (5) ◽  
pp. 492-509 ◽  
Author(s):  
N. D. Diamantides
Keyword(s):  
Solar Activity ◽  
Time Course ◽  
Analytical Tool ◽  
The Sun ◽  
Nonlinear Part ◽  
The Past ◽  
Research Task ◽  
Present Context ◽  
Long Term Behavior

Abstract. The research task described herein aims at the structuring of an analytical tool that traces the time course of geophysical phenomena, regional or global, and compares it to the course of long-term solar conditions, long-term meaning decades or a few centuries. The model is based on the premise that since in a last analysis the preponderance of atmospheric, hydrospheric, and, possibly, some aspects of geospheric phenomena are, or have been, powered by energy issuing from the sun - either now or in the past - the long-term behavior of such phenomena is ultimately "connected" to long-term changes occurring in the sun itself. Accordingly, the proposed research firstly derives and models a stable surrogate pattern for the long-term solar activity, secondly introduces a transfer-function algorithm for modeling the connection between the surrogate and terrestrial phenomena viewed as partners in the connection, and thirdly probes the connection outcome for episodic or unanticipated effects that may arise due to the fact that in the present context, the connection, should it exist, is very likely nonlinear. Part I of the study presents the theory of the concept, while Part II demonstrates the concept's pertinence to a number of terrestrial phenomena.Key words. Solar activity · Kolmogorov algorithm

scholarly journals Solar Activity of the Past 100 Years Inferred From 10 Be in Ice Cores—Implications for Long‐Term Solar Activity Reconstructions

2021 ◽  
Vol 48 (4) ◽  
Author(s):  
Minjie Zheng ◽  
Florian Adolphi ◽  
Jesper Sjolte ◽  
Ala Aldahan ◽  
Göran Possnert ◽  
...  
Keyword(s):  
Solar Activity ◽  
Ice Cores ◽  
The Past

A long-term geophysical and astronomical dataset: sunspot counting from 1610 to 2021

2021 ◽  
Author(s):  
José M. Vaquero
Keyword(s):  
Solar Activity ◽  
19Th Century ◽  
Sunspot Number ◽  
Solar Physics ◽  
The Sun ◽  
Essential Factor ◽  
The Past ◽  
The 19Th Century ◽  
Made In

<p>Solar activity is an essential factor for the study of many aspects of the geophysical and astronomical sciences. A very simple measure of solar activity is counting sunspots using telescopes. This task can be done even with small telescopes since the Sun is apparently a very large and luminous star. For this reason, it is possible to rescue the ancient observations of sunspots made in the past centuries to obtain an image of the evolution of solar activity during the last four centuries.</p><p>The first attempt to reconstruct solar activity from these records was made by Rudolf Wolf, who defined the <em>Sunspot Number</em> index in the 19th century. The Zurich Observatory (and later the Brussels Observatory) was in charge of continuing Wolf's work to the present day. In 1998, Hoyt and Schatten presented a new reconstruction of solar activity that was very different from Wolf's reconstruction (Vaquero and Vázquez, 2009). Many of these differences were solved by Clette et al. (2014).</p><p>Currently, research to improve the <em>Sunspot Number</em> is focused on (i) improving the database by reviewing old observations, and (ii) improving the methodologies to convert raw data into the <em>Sunspot Number</em> index. In this work, we try to present the latest advances in this task (Muñoz-Jaramillo and Vaquero, 2019; Arlt and Vaquero, 2020).</p><p> </p><p>References</p><p>Arlt, R., Vaquero, J.M. (2020) Living Reviews in Solar Physics 17, 1.</p><p>Clette, F. et al. (2014) Space Science Reviews 186, 35.</p><p>Muñoz-Jaramillo, A., Vaquero, J.M. (2019) Nature Astronomy 3, 205.</p><p>Vaquero, J.M. and Vázquez, M. (2009) The Sun recorded through history (Springer).</p>

scholarly journals Long-term solar activity and terrestrial connections. Part I: theory

1998 ◽  
Vol 16 (5) ◽  
pp. 479-491
Author(s):  
N. D. Diamantides
Keyword(s):  
Solar Activity ◽  
Time Course ◽  
Analytical Tool ◽  
The Sun ◽  
Nonlinear Part ◽  
The Past ◽  
Research Task ◽  
Present Context ◽  
Long Term Behavior

Abstract. The research task described herein aims at the structuring of an analytical tool that traces the time course of geophysical phenomena, regional or global, and compares it to the course of long-term solar conditions, long-term meaning decades or a few centuries. The model is based on the premise that since in a last analysis the preponderance of atmospheric, hydrospheric, and, possibly, some aspects of geospheric phenomena are, or have been, powered by energy issuing from the sun – either now or in the past, the long-term behavior of such phenomena is ultimately "connected" to long-term changes occurring in the sun itself. Accordingly, the proposed research firstly derives and models a stable surrogate pattern for the long-term solar activity, secondly introduces a transfer-function algorithm for modeling the connection between the surrogate and terrestrial phenomena viewed as partners in the connection, and thirdly probes the connection outcome for episodic or unanticipated effects that may arise due to the fact that in the present context, the connection, should it exist, is very likely nonlinear. Part I of the study presents the theory of the concept, while Part II demonstrates the concept's pertinence to a number of terrestrial phenomena.Key words. Solar activity · Kolmogorov algorithm

Solar observations in ancient China and solar variability

1990 ◽  
Vol 330 (1615) ◽  
pp. 513-515 ◽  
Keyword(s):  
Solar Activity ◽  
Power Spectrum ◽  
Solar Variability ◽  
Ancient China ◽  
Naked Eye ◽  
The Third ◽  
Solar Observations ◽  
History Of ◽  
Long Term Variations

In this paper I review both the history of solar observations in ancient China and recent researches on solar variability. The paper consists of three parts. In the first part I describe Sun worship and the early observations of solar phenomena. In the second part I concentrate on sunspot observations and improving the catalogue of naked-eye sunspot records. In the third part I discuss long-term variations of solar activity by using historical sunspot records over 2000 years. The 210-year cycle, which has the largest significance in the power spectrum, may have an important influence on the forecasting of the next cycle (no. 22).

A Study of Variation of the 11-yr Solar Cycle before the onset of the Spoerer Minimum based on Annually measured 14C Content in tree Rings

Radiocarbon ◽  
2019 ◽  
Vol 61 (6) ◽  
pp. 1749-1754 ◽  
Author(s):  
Toru Moriya ◽  
Hiroko Miyahara ◽  
Motonari Ohyama ◽  
Masataka Hakozaki ◽  
Mirei Takeyama ◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Cycle Length ◽  
Detailed Mechanism ◽  
Grand Minimum ◽  
The Past ◽  
Shimokita Peninsula ◽  
Solar Cycle Length ◽  
Long Term Variations

ABSTRACTProxy-based observations of solar activity in the past have revealed long-term variations, such as the Gleissberg cycle (~88 yr), de Vries cycle (~200 yr), and the Hallstatt cycle (~2000 yr). Such long-term variations of solar activity sometimes cause the disappearance of sunspots for several decades. Currently, solar activity is becoming weaker, and there is a possibility that another long-term sunspot minimum could occur. However, the detailed mechanism of the weakening in solar activity is unknown, and the prediction of solar activity is ambiguous. In this study, we investigate the transitions of solar cycle length before the onset of the Spoerer Minimum, the longest grand minimum in the past 2000 yr. We measured the 14C content in an asunaro tree (Thujopsis dolabrata) excavated at Shimokita Peninsula from 1368–1420 CE using the compact AMS system at Yamagata University. It is found that the solar cycle lengthened to be 14–16 yr from 2 cycles before the onset of the Spoerer Minimum.

scholarly journals Historical records of solar grand minima: a review

2011 ◽  
Vol 7 (S286) ◽  
pp. 383-392 ◽  
Author(s):  
José M. Vaquero
Keyword(s):  
Solar Activity ◽  
Recent Progress ◽  
Maunder Minimum ◽  
Historical Records ◽  
Naked Eye ◽  
Solar Diameter ◽  
Grand Minimum ◽  
The Past ◽  
Grand Minima

AbstractKnowing solar activity during the past centuries is of great interest for many purposes. Historical documents can help us to know about the behaviour of the Sun during the last centuries. The observation of aurorae and naked-eye sunspots provides us with continuous information through the last few centuries that can be used to improve our knowledge of the long-term solar activity including solar Grand Minima. We have more or less detailed information on only one Grand minimum (the Maunder minimum in the second half of 17th century), which serves as an archetype for Grand minima in general. Telescopic sunspot records and measurements of solar diameter during Maunder minimum are available. In this contribution, I review some recent progress on these issues.

scholarly journals Estimation of permafrost thawing rates in a sub-arctic catchment using recession flow analysis

2009 ◽  
Vol 6 (1) ◽  
pp. 63-83 ◽  
Author(s):  
S. W. Lyon ◽  
G. Destouni ◽  
R. Giesler ◽  
C. Humborg ◽  
M. Mörth ◽  
...  
Keyword(s):  
Average Rate ◽  
Flow Analysis ◽  
Local Scale ◽  
Northern Sweden ◽  
The Past ◽  
Direct Observations ◽  
Flow Pathways ◽  
Thawing Rate ◽  
Permafrost Thawing

Abstract. Permafrost thawing is likely to change the flow pathways taken by water as it moves through arctic and sub-arctic landscapes. The location and distribution of these pathways directly influence the carbon and other biogeochemical cycling in northern latitude catchments. Direct observations of permafrost depth are difficult to perform at scales larger than a local scale. Using recession flow analysis, it may be possible to detect and estimate the rate of permafrost thawing based on a long-term streamflow record. We demonstrate the application of this approach to the sub-arctic Abiskojokken catchment in northern Sweden. Based on recession flow analysis, we estimate that permafrost in this catchment may be thawing at an average rate of about 0.9 cm/yr during the past 90 years. This estimated thawing rate is consistent with direct observations of permafrost thawing rates, ranging from 0.7 to 1.3 cm/yr over the past 30 years in the region.

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