![Number of Chinese counties reporting frost or snow, 1490-1680. Notice the absence of reports from the 1640s. (Source compiled from Guangdong sheng ziran zaihai shilian. [Guangzhou : Guangdong sheng wenshi yanjiu guan, 1961] in p. 139 of R. Marks 1998).](https://www.researchgate.net/profile/Steven-Yaskell/publication/335950578/figure/fig2/AS:805308683268096@1569011960919/Number-of-Chinese-counties-reporting-frost-or-snow-1490-1680-Notice-the-absence-of_Q320.jpg)
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The Maunder Minimum and the Variable Sun-Earth Connection
Abstract and Figures
Soon-Yaskell book (2003,) on E.W. Maunder, his wife, and the work leading up to the discovery of the Maunder Minimum and its relation to solar variability.
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... Studying similar stars' magnetic activity offers a more efficient way to validate these models. For example, surface magnetic activity records of stars on or near the lower main sequence (e.g. from the Mount Wilson Observatory Ca II H and K survey, Soon & Yaskell 2003) show variability similar to the solar variability, including Maunder minimum-like phases, on time scales of many decades. Figure 2.2 shows a K2 star (HD 166620) with an activity cycle like that of the Sun, showing a rapid decline in its chromospheric activity as it enters into a Maunder-minimum state. ...
This report presents the findings of a NIAC Phase I feasibility study for the Artemis-enabled Stellar Imager (AeSI), a proposed high-resolution, UV/Optical interferometer designed for deployment on the lunar surface. Its primary science goal is to image the surfaces and interiors of stars with unprecedented detail, revealing new details about their magnetic processes and dynamic evolution and enabling the creation of a truly predictive solar/stellar dynamo model. This capability will transform our understanding of stellar physics and has broad applicability across astrophysics, from resolving the cores of Active Galactic Nuclei (AGN) to studying supernovae, planetary nebulae, and the late stages of stellar evolution. By leveraging the stable vacuum environment of the Moon and the infrastructure being established for the Artemis Program, AeSI presents a compelling case for a lunar-based interferometer. In this study, the AeSI Team, working with the NASA Goddard Space Flight Center's Integrated Design Center (IDC), has firmly established the feasibility of building and operating a reconfigurable, dispersed aperture telescope (i.e., an interferometer) on the lunar surface. The collaboration produced a credible Baseline design featuring 15 primary mirrors arranged in an elliptical array with a 1 km major axis, with the potential to expand to 30 mirrors and larger array sizes through staged deployments. Additionally, this study identified numerous opportunities for optimization and the necessary trade studies to refine the design further. These will be pursued in follow-up investigations, such as a NIAC Phase II study, to advance the concept toward implementation.
... In addition, some evidence has been found suggesting that solar cycle was still in progress during the MM (e.g. Beer et al. 1998;Soon & Yaskell 2003;Vaquero et al. 2015). After the solar MM end, it was followed by a gradual increase in cycle amplitudes of the cyclic variability (Hathaway 2015). ...
We perform, for the first time, a detailed long-term activity study of the binary system Ret. We use all available HARPS spectra obtained between the years 2003 and 2016. We built a time series of the Mount Wilson S index for both stars, then we analyse these series by using Lomb-Scargle periodograms. The components Ret and Ret that belong to this binary system are physically very similar to each other and also similar to our Sun, which makes it a remarkable system. We detect in the solar-analogue star Ret a long-term activity cycle with a period of 10 yr, similar to the solar one (11 yr). It is worthwhile to mention that this object satisfies previous criteria for a flat star and for a cycling star simultaneously. Another interesting feature of this binary system, is a high 0.220 dex difference between the averages log() activity levels of both stars. Our study clearly shows that Ret is significantly more active than Ret. In addition, Ret shows an erratic variability in its stellar activity. In this work, we explore different scenarios trying to explain this rare behaviour in a pair of coeval stars, which could help to explain the difference in this and other binary systems. From these results, we also warn that for the development of activity-age calibrations (which commonly use binary systems and/or stellar clusters as calibrators) it should be taken into account the whole history of activity available of the stars involved.
Several total solar irradiance (TSI) satellite missions have been carried out since 1978. None of these missions have lasted more than one to two solar cycles (SCs), and each mission implies a slightly different absolute TSI baseline. Nonetheless, several satellite composites have been developed by compositing satellite data from different missions to form an almost continuous daily record for the satellite era. However, disconcertingly, each mission has implied slightly different changes in TSI between consecutive solar minima and solar maxima. Some groups have developed adjustments to individual missions that have substantially reduced these differences. Others prefer to use the original data published by the satellite science teams. Some TSI composites average together conflicting records, while others prioritize specific records over others. Here, we compare four existing composites to 17 new alternative series based on the available satellite data. These 21 TSI series are statistically sorted into six groups of three to four series each. We found that the six groups suggest different intercycle trends between solar minima. We compare the groups to eight daily resolved solar proxy-based TSI reconstructions and to daily sunspot numbers. Excellent agreement is obtained over one to two SCs, but significant differences are observed over longer timescales for each group. Therefore, we have assembled all these time series (old and new) into a large and new TSI data set for use by the scientific community. Versions scaled to 1 au (for studying solar variability) or in situ values at Earth (for studying solar/terrestrial interactions) are provided at daily, monthly, and yearly resolutions.
Within four centuries of sunspot observations, the Maunder Minimum (MM) in 1645–1715 has been considered a unique grand minimum with weak solar cycles in group numbers of sunspots and hemispheric asymmetry in sunspot positions. However, the early part of the MM (1645–1659) is poorly understood in terms of its source records and has accommodated diverse reconstructions of the contemporaneous group number. This study identified their source records categorise them in three different categories (datable observations, general descriptions, and misinterpreted records) and revised their data. On this basis, we estimated the yearly mean group number using the brightest-star method, derived the active day fraction, reconstructed the sunspot number, and compared them with proxy reconstructions from the tree-ring datasets. Our results revised the solar activity in the early MM downward in yearly mean group numbers using the brightest-star method and upward in the active day fraction and sunspot number estimates. Our results are consistent with the proxy reconstruction for 1645–1654 and show more realistic values for 1657–1659 (against the unphysical negative sunspot number). These records have paid little attention to sunspot position, except for the report of Hevelius on a sunspot group in the northern solar hemisphere in Apr 1652. Therefore, slight caveats are required to discuss if the sunspot positions are located purely in the southern solar hemisphere throughout the MM.
On a centennial timescale, solar activity oscillates quasi-periodically and also tends to get into a low-activity period. The Dalton Minimum (c.a. 1790s–1820s) was one of such low-activity periods that had been captured in telescopic sunspot observations. However, it has been challenging to analyse the Dalton Minimum, as contemporary source records remained mostly unpublished and almost inaccessible for the scientific community. Recent studies have established reliable datasets for sunspot group number, sunspot number, and sunspot positions. This study further analyzes independent Silesian sunspot observations from 1800 to 1827 archived in a manuscript the Library WrocławUniversity (Ms AKC.1985/15), complements it with the metadata for the observer Karl Christian Reinhold von Lindener. We identified 547 days of sunspot observations in these records and derived the sunspot group number, individual sunspot number, and sunspot positions between 1800 and 1827. The results of this study have significantly revised the von Lindener’s sunspot group number, which was only known for 517 days in scientific databases, and remove contamination from general descriptions. Using our results, we extend investigations into individual sunspots and derived their positions. In our analysis, we locate von Lindener’s sunspot positions in both solar hemispheres and contrast the Dalton Minimum with the Maunder Minimum, adding further independent credits to the previous results for Derfflinger and Prantner’s datasets. Sunspot positions are also slightly biased towards the northern solar hemisphere in early Solar Cycle 6 (1812 – 1813). The high-latitude sunspot positions indicate the onset of Solar Cycle 7 as early as June 1822.
The temporal spectrum of the solar activity is more than just the main cycle. It contains different timescales, which can be considered as continuous components of the activity spectrum. The possibility of finding a realistic spectrum of the solar magnetic activity variation is analysed for several versions of a simple model for solar activity based on the original idea of E. Parker. In particular, we study the original set of partial differential equations with two versions of suppression of the dynamo action and the fourth-order dynamical system obtained by truncating the Parker equations. We show that the effects included in the models, i.e. the nonlinear dynamo suppression and the dynamical chaos, as well as random fluctuations of the dynamo drivers, are quite sufficient to obtain the main solar cycle and the continuous components of the spectrum similar to the observed ones. However, the capabilities of the approach under consideration substantially vary from one model to another. Each model reproduces a continuous component of the spectrum in a specific parameter range. This study has confirmed the view that the examination of various solar dynamo models with the aim to find a reasonable combination of main activity cycle and continuous spectrum of solar activity can be used as an additional test of their validity.
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Variations must take place in the ocean circulation when the general wind circulation varies. There are hints even within recent years that the variations in the ocean between Iceland and Scotland and Norway can be big: The area has been regarded as the main path of the warm, saline North Atlantic Drift water heading towards the Arctic; but, when the polar water occasionally intrudes from the north, sea-surface temperature is liable to fall by 3 to 5°C and presumably by more than this when, as in 1888, the ice advanced to near the Faeroe Islands. The long series of sea-surface temperature observations at that point, starting in 1867, and earlier observations covering the area in 1789, are studied. Various kinds of proxy data—notably the CLIMAP Atlantic ocean-bed core analysis results for the last Ice Age climax and cod fishery and sea-ice reports from the Little Ice Age in the 17th century ad—are then used to indicate the variability in this part of the ocean on longer time scales. The reconstruction of the situation between ad 1675 and 1705 resulting from this study suggests a probable mean departure of the sea surface temperature from modern values between the Faeroes and southeast Iceland amounting to about −5°C; and at the climax in 1695 the polar water seems to have spread all around Iceland, across the entire surface of the Norwegian Sea to Norway, and south to near Shetland. Support for this diagnosis is found in a considerable variety of reports of environmental conditions existing at the time in Scotland, south Norway and elsewhere. The enhanced thermal gradient between approximately latitudes 55 and 65°N during the Little Ice Age, which this result indicates, offers an explanation for the occurrence in that period of a number of windstorms which changed the coasts in various places and seem to have surpassed in intensity the worst experienced in the region in more recent times.
This book is a study of the development and history of climate. It is intended to meet a variety of needs. Students of meteorology and climatology and workers in other disciplines concerned with the impact of climate upon human affairs, upon the animal and plant kingdoms and upon the surface of the Earth itself, will find in it an account of what makes climates what they are, and of how they vary and have varied. Practical men - farmers, engineers, industrialists and especially those concerned with long-term economic development and planning - may gain from it a new appIeciation of things to be allowed for where climate affects, or might come to affect, their schemes.
Introduction: the climate problem. Part 1 The development of climate: how climate works how climate comes to fluctuate and change how we can reconstruct the past record of climate. Part 2 Climate and history: climate at the dawn of history in the times of early civilizations times of disturbance and decline in the ancient world Roman times and after through Viking times to the high Middle Ages decline again in the late Middle Ages the little Ice Age - background to the history of the 16th and 17th centuries the recovery - 1700 to c.1950. Part 3 Climate in the modern world and questions over the future climate since 1950 the impact of climatic developments on human affairs and human history the causes of climate's fluctuations and changes forecasting developments over recent decades.
Evidence is summarised here that trees store a record of atmospheric temperature in their rings. In each ring, the ratios of the stable isotopes of hydrogen and oxygen vary with the air temperature prevailing when the ring was formed. We have shown that the temperature records in three modern trees seem to follow the local mercury thermometer records, and have found that a Japanese cedar indicates a temperature fall of ~1.5°C in the past 1,800 yr.