Association between gestational exposure to solar activity and pregnancy loss using live births from a Massachusetts-based medical center.

BACKGROUND: Solar activity has been linked to biological mechanisms important to pregnancy, including folate and melatonin levels and inflammatory markers. Thus, we aimed to investigate the association between gestational solar activity and pregnancy loss. METHODS: Our study included 71,963 singleton births conceived in 2002-2016 and delivered at an academic medical center in Eastern Massachusetts. We studied several solar activity metrics, including sunspot number, Kp index, and ultraviolet radiation, with data from the NASA Goddard Space Flight Center and European Centre for Medium-Range Weather Forecasts. We used a novel time series analytic approach to investigate associations between each metric from conception through 24 weeks of gestation and the number of live birth-identified conceptions (LBICs) -the total number of conceptions in each week that result in a live birth. This approach fits distributed lag models to data on LBICs, adjusted for time trends, and allows us to infer associations between pregnancy exposure and pregnancy loss. RESULTS: Overall, the association between solar activity during pregnancy and pregnancy loss varied by exposure metric. For sunspot number, we found that an interquartile range increase in sunspot number (78·7 sunspots) in all of the first 24 weeks of pregnancy was associated with 14·0 (95% CI: 6·5, 21·3) more pregnancy losses out of the average 92 LBICs in a week, and exposure in weeks ten through thirteen was identified as a critical window. Although not statistically significant, higher exposure to Kp index and to UV radiation across all 24 weeks of pregnancy was associated with more and less pregnancy losses, respectively. CONCLUSION: While exposure to certain metrics of solar activity (i.e., sunspot number) throughout the first 24 weeks of pregnancy may be associated with pregnancy losses, exposure to other metrics were not. Solar activity is a complex phenomenon, and more studies are needed to clarify underlying pathways.

Intense solar activity reduces urinary 6-sulfatoxymelatonin in patients with COPD.

BACKGROUND: Little is known about the link between solar activity and variations in melatonin. In this study, we investigated if melatonin's major urinary metabolite, urinary 6-sulfatoxymelatonin (aMT6s), is lowest under periods of intense solar activity. METHODS: We investigated associations between high-energy solar particle events [Coronal Mass Ejection (CME) mass, speed and energy] on creatinine-adjusted aMT6s (aMT6sr) concentrations in 140 patients with chronic obstructive pulmonary disease (COPD) using up to four seasonal urine samples (n = 440). Mixed effect models with a random intercept for each subject were used to estimate associations, including effect modification attributable to diabetes, obesity, and reduced pulmonary function. RESULTS: Higher values of CME were associated with reduced aMT6sr concentrations, with stronger associations in patients with diabetes. An interquartile range (IQR) increase in natural log CMEspeed averaged through two days before urine collection was associated with a reduction of 9.3% aMT6sr (95%CI: - 17.1%, - 0.8%) in aMT6sr. There was a greater reduction in aMT6sr in patients with diabetes (- 24.5%; 95%CI: - 35.9%, - 11.6%). In patients without diabetes there was no meaningful association (- 2.2%; 95%CI: - 12%, 8.4%). There were similar associations with CMEenergy and CMEmass. There was no effect modification attributable to reduced pulmonary function or obesity. CONCLUSIONS: This is the first study in patients with COPD to demonstrate strong detrimental impact of high-energy solar particle events on aMT6sr, with greater associations in patients with diabetes. Since melatonin is an anti-oxidant, it is possible that adverse effects of intense solar activity may be attributable to a reduction in circulating melatonin and that patients with both COPD and diabetes may be more susceptible.

Space weather phenomena on heart rate: a study in the Greek region.

Many scientific investigations have focused on how space weather phenomena, taking place in the vicinity of the Earth, may influence different aspects of life on Earth and presumably human health itself. From 2005, the National and Kapodistrian University of Athens has established an important position in the field of these investigations by collaborating with various scientists and Institutes, both international and domestic, in different heliobiological projects. In this work, the Cosmic Ray Group of the National and Kapodistrian University of Athens has co-operated with the medical staff from different hospitals and clinics around the country so as to develop large records of medical data (heart rate) which covers a long time period. These data are analyzed in regard to physical activity, either on a daily basis or on different levels of geomagnetic disturbances and variations of the cosmic ray intensity using the ANalysis Of Variance (ANOVA) and the multiple linear regression analysis. Results suggest that space weather phenomena may be related to heart rate variability, i.e., heart rate is statistically significantly effected either by variations of cosmic rays intensity or geomagnetic activity.

The role of teleconnections and solar activity on the discharge of tropical river systems within the Niger basin.

The behavior of tropical river systems is driven by some internal and external factors. Understanding the role of these external forces, such as large-scale oscillations, on river discharge will provide insight into their dynamic complexities and modelling. In this study, the role of teleconnection patterns and solar activity on river discharges within the Niger basin was considered using both linear (correlation) and nonlinear (multifractal and joint recurrence analysis) statistical approaches. Correlation analysis suggests the existence of a linear relationship between tropical teleconnection patterns in the Atlantic and Pacific oceans with river discharge in the Niger basin. Nonlinear relationships were investigated using multifractal formalism and joint recurrence quantification analysis. A strong nonlinear relationship was observed between the teleconnection patterns and river discharge in Diola while other stations (Koulikoro, Ansongo, Niamey, Mopti, Kirango) showed no such relationship. The observation at Diola is attributed to its location (coastal) among other things. The multifractal strengths were found in the range of 0.58-2.86, suggesting fractal correlations between the parameters. There was no conclusive evidence of a linear and nonlinear relationship between solar activity and tropical river discharge within the Niger basin.

Unknown effects of daily-scale solar activity on the plant growth: Data from 6-year growth monitoring of Sphagnum riparium.

The influence of solar activity on plant growth has been studied for over 100 years, however, this phenomenon is still poorly understood on a daily scale. The data from extensive monitoring of the growth of peat moss Sphagnum riparium, which we are conducting in the mires of Karelia (Russia), may shed light on this issue. During the 6 years of observation, 161,190 shoots were measured, and 1075 growth rates were obtained. Considering together the growth rates with the sunspot number and involving data on seasonal temperature, we found previously unknown effects of daily-scale solar activity on plant growth. It was found that the sunspot number weakly but significantly inhibits the growth of Sphagnum. The extreme sunspot number in the 4 days before the growth rate values have a stronger influence. The involvement of temperature data showed that inhibition in growth is observed only in the temperature range from 6.7°C to 15.3°C and disappears beyond these limits. In addition, the data obtained showed that the influence of sunspot number on the growth of Sphagnum is progressively increasing along the gradient from the minimum to the maximum of the 11-year solar cycle. The study provides one of the first results on the effect of solar activity on plant growth on a daily scale. The results expand our knowledge of the biological effects of solar activity. Indirectly, they can also be useful to better our understanding of the ozone layer's involvement in this process.

Spatiotemporal hysteresis distribution and decomposition of solar activities and climatic oscillation during 1900-2020.

Solar radiation is the external driving force of the Earth's climate system. In different spatial and temporal scales, meteorological elements have different responses and lag periods to solar activity (SA), climatic oscillation (CO), geographic factors (GF) and other influencing factors. However, such studies are not abundant and in-depth in the world. To further understand the "solar-climate-water resource" system, this study considers China as the study area and investigates the monthly data of temperature (T) and precipitation (P) during 1900-2020 that were obtained from 3836 grid stations. The strong interaction and lag distribution between T or P with SA and CO were studied and influence weights of SA, CO, and geographical factors (GF) of each grid station were calculated. A multivariate hysteretic decomposition model was established to simulate and quantitatively decompose the periodic lag considering the factors of the earth's revolution. It is found that the strong interaction/lag periods obtained in a long-time scale can be decomposed into several periods shorter than the SA period. The distribution of strong interaction/lag periods is nested with topography and echoes with cities. The underlying surface conditions and urbanization are also important factors affecting the T and P lag. There are two distinct dividing lines in the lag period and influencing factor pattern of T and P. The T dividing line moves through valleys where water or mountain ranges meet, where the gap facilitates monsoon movement across regions, while the P dividing line is a zone of dramatic terrain, where tall mountains block water vapor transport. In the lag trend of T, the northern region of China has the longest lag period, and the lag period of surrounding regions tends to converge to the northern region. The lag period caused by SN in southwest China is larger than that in northwest China, while the lag effect of CO is opposite in the above two regions. The lag trend of P also has the above characteristics, but the difference is that the lag period in central China is the longest.

About 4-Day Rhythm of Proliferative Activity of L-929 Cells in Culture Correlates with the Intensity of Secondary Cosmic Radiation Fluctuations.

The dynamics of proliferative activity of the L-929 cell culture of mouse fibroblast-like cells in the phase of logarithmic growth was compared with some heliogeophysical parameters (Ap and ULF indexes of geomagnetic activity, vertical component of the interplanetary magnetic field, and intensity of fluctuations of secondary cosmic radiation estimated by the neutron monitoring near the Earth's surface). Among the considered heliogeophysical parameters, only the magnitude of fluctuations of minute-to-minute changes in the neutron monitor indicator reliably and negatively correlates with the rate of cell culture reproduction. Considering that the amplitude of secondary cosmic fluctuations is about 5%, which is 0.1% of the total ray flux, and proliferative activity varies in the range of 30-50%, the probability of a direct biotrophic effect of this physical factor is extremely low. It seems likely that proliferative activity of L-929 cell culture is directly affected by another environmental factor, the marker of which is the intensity of neutron counting rate fluctuations.

The impact of solar activity on ambient ultrafine particle concentrations: An analysis based on 19-year measurements in Boston, USA.

Solar radiation plays a major role in atmospheric photochemistry, contributing to the formation and growth of ultrafine particles (PN). PN affect global Earth's radiation balance, climate system, and human health. However, the impact of solar activity on ambient PN remains unclear. In this study, we investigated the associations between daily ambient PN concentrations [particle number (PN)/cm3] and solar radio flux [solar activity index (F10.7 in sfu)] as a solar activity parameter, shortwave solar radiation (SWR), daylight time (DL), cosmic ray-induced ionization (CRII), and air pollution [PM2.5, black carbon (BC) and SO2] over a 19-year period in Boston, MA. We used generalized additive models adjusted for local environmental conditions. We found that F10.7 was the strongest predictor for daily PN concentrations over all time lags (0-28 days of lags) and seasons. The effects were higher in winter and fall. In winter, an interquartile (IQR) of 60 sfu F10.7 corresponded to an increase of 5770 PN/cm3 in the day of PN collection. In fall, an IQR of 75.5 sfu F10.7 was associated with an increase of 5429 PN/cm3. The effects of F10.7 on PN concentrations were slightly greater when the models were adjusted for air pollution. In summer, ambient PN concentrations were statistically significantly associated with F10.7, SWR, and BC, with the strongest association found for PN and BC in the day of PN collection. Unlike the effects of F10.7, SWR and local pollutants on PN concentrations, DL and CRII were negatively associated with ambient PN in the analyses. These findings suggest that solar activity may have a significant impact on daily ambient PN concentrations that affect the Earth's climate system and human health.

Systemic lupus Erythematosus and geomagnetic disturbances: a time series analysis.

BACKGROUND: To examine the influence of solar cycle and geomagnetic effects on SLE disease activity. METHODS: The data used for the analysis consisted of 327 observations of 27-day Physician Global Assessment (PGA) averages from January 1996 to February 2020. The considered geomagnetic indices were the AP index (a daily average level for geomagnetic activity), sunspot number index R (measure of the area of solar surface covered by spots), the F10.7 index (measure of the noise level generated by the sun at a wavelength of 10.7 cm at the earth's orbit), the AU index (upper auroral electrojet index), and high energy (> 60 Mev) proton flux events. Geomagnetic data were obtained from the Goddard Space Flight Center Space Physics Data Facility. A time series decomposition of the PGA averages was performed as the first step. The linear relationships between the PGA and the geomagnetic indices were examined using parametric statistical methods such as Pearson correlation and linear regression, while the nonlinear relationships were examined using nonparametric statistical methods such as Spearman's rho and Kernel regression. RESULTS: After time series deconstruction of PGA averages, the seasonality explained a significant fraction of the variance of the time series (R2 = 38.7%) with one cycle completed every 16 years. The analysis of the short-term (27-day) relationships indicated that increases in geomagnetic activity Ap index (p < 0.1) and high energy proton fluxes (> 60 Mev) (p < 0.05) were associated with decreases in SLE disease activity, while increases in the sunspot number index R anticipated decreases in the SLE disease activity expressed as PGA (p < 0.05). The short-term correlations became statistically insignificant after adjusting for multiple comparisons using Bonferroni correction. The analysis of the long-term (297 day) relationships indicated stronger negative association between changes in the PGA and changes in the sunspot number index R (p < 0.01), AP index (p < 0.01), and the F10.7 index (p < 0.01). The long-term correlations remained statistically significant after adjusting for multiple comparisons using Bonferroni correction. CONCLUSION: The seasonality of the PGA averages (one cycle every 16 years) explains a significant fraction of the variance of the time series. Geomagnetic disturbances, including the level of geomagnetic activity, sunspot numbers, and high proton flux events may influence SLE disease activity. Studies of other geographic locales are needed to validate these findings.

Methods and Experiments for Sensing Variations in Solar Activity and Defining Their Impact on Heart Variability.

This paper evaluates variations in solar activity and their impact on the human nervous system, including the manner in which human behavior and decision-making reflect such effects in the context of (symmetrical) social interactions. The relevant research showed that solar activity, manifesting itself through the exposure of the Earth to charged particles from the Sun, affects heart variability. The evaluation methods focused on examining the relationships between selected psychophysiological data and solar activity, which generally causes major alterations in the low-level electromagnetic field. The investigation within this paper revealed that low-level EMF changes are among the factors affecting heart rate variability and, thus, also variations at the spectral level of the rate, in the VLF, (f = 0.01-0.04 Hz), LF (f = 0.04-0.15 Hz), and HF (f = 0.15 az 0.40 Hz) bands. The results of the presented experiments can also be interpreted as an indirect explanation of sudden deaths and heart failures.

Exploring the relationship between geomagnetic activity and human heart rate variability.

PURPOSE: Both geomagnetic and solar activity fluctuate over time and have been proposed to affect human physiology. Heart rate variability (HRV) has substantial health implications regarding the ability to adapt to stressors and has been shown to be altered in many cardiovascular and neurological disorders. Intriguingly, previous work found significant, strong correlations between HRV and geomagnetic/solar activity. The purpose of this study to replicate these findings. We simultaneously measured HRV during a 30-day period. METHODS: We recruited 20 healthy participants and measured their HRV for a 30-day period. We also collected geomagnetic and solar activity during this period for investigating their relationship with the HRV data. RESULTS: In agreement with previous work, we found several significant correlations between short-term HRV and geophysical time-series. However, after correction for autocorrelation, which is inherent in time-series, the only significant results were an increase in very low frequency during higher local geomagnetic activity and a geomagnetic anticipatory decrease in heart rate a day before the higher global geomagnetic activity. Both correlations were very low. The loss of most significant effects after this correction suggests that previous findings may be a result of autocorrelation. A further note of caution is required since our and the previous studies in the field do not correct for multiple comparisons given the exploratory analysis strategy. CONCLUSION: We thus conclude that the effects of geomagnetic and solar activity are (if present) most likely of very small effect size and we question the validity of the previous studies given the methodological concerns we have uncovered with our work.

Associations between Quasi-biennial Oscillation phase, solar wind, geomagnetic activity, and the incidence of acute myocardial infarction.

An increase in the daily rate of acute myocardial infarction (AMI) has been observed during days of geomagnetic storm (GS). However, the analysis of associations between the daily number of AMI and geomagnetic activity (GMA) over longer periods sometimes yields controversial results. The study aimed to detect the complex association between the daily numbers of AMI and weather, the Quasi-biennial Oscillation (QBO) phase, GMA, and solar wind variables. We used data of Kaunas population-based Ischemic Heart Disease Register of residents of Kaunas city (Lithuania) for 2000-2012. The associations between weather and space weather variables and the daily number of AMI were evaluated by applying the multivariate Poisson regression. A higher risk of AMI was positively associated with active-stormy local GMA (rate ratio (RR) = 1.06 (95% CI 1.01-1.10)), solar wind dynamic pressure with a lag of 4 days (RR = 1.02 (1.01-1.04) per 1 nPa increase), and solar wind speed with a lag of 3-7 days (RR = 1.03 (1.01-1.05) per 100 km/s increase). A positive association was found between the west QBO phase and the risk of AMI during winter (RR = 1.08 (1.01-1.16)), and a negative association was observed between them during March-November (RR = 0.93 (0.90-0.97)). The risk of AMI positively associated with the GS due to stream interaction regions with a lag of 0-2 days during the east QBO phase (RR = 1.10, p = 0.046) and was negatively associated with them during the west QBO phase (RR = 0.82, p = 0.024). These results may help understand the population's sensitivity under different weather and space weather conditions. The QBO phase may modify the effect of GS.

Insolation-induced mid-Brunhes transition in Southern Ocean ventilation and deep-ocean temperature.

Glacial-interglacial cycles characterized by long cold periods interrupted by short periods of warmth are the dominant feature of Pleistocene climate, with the relative intensity and duration of past and future interglacials being of particular interest for civilization. The interglacials after 430,000 years ago were characterized by warmer climates and higher atmospheric concentrations of carbon dioxide than the interglacials before, but the cause of this climatic transition (the so-called mid-Brunhes event (MBE)) is unknown. Here I show, on the basis of model simulations, that in response to insolation changes only, feedbacks between sea ice, temperature, evaporation and salinity caused vigorous pre-MBE Antarctic bottom water formation and Southern Ocean ventilation. My results also show that strong westerlies increased the pre-MBE overturning in the Southern Ocean via an increased latitudinal insolation gradient created by changes in eccentricity during austral winter and by changes in obliquity during austral summer. The stronger bottom water formation led to a cooler deep ocean during the older interglacials. These insolation-induced differences in the deep-sea temperature and in the Southern Ocean ventilation between the more recent interglacials and the older ones were not expected, because there is no straightforward systematic difference in the astronomical parameters between the interglacials before and after 430,000 years ago. Rather than being a real 'event', the apparent MBE seems to have resulted from a series of individual interglacial responses--including notable exceptions to the general pattern--to various combinations of insolation conditions. Consequently, assuming no anthropogenic interference, future interglacials may have pre- or post-MBE characteristics without there being a systematic change in forcings. These findings are a first step towards understanding the magnitude change of the interglacial carbon dioxide concentration around 430,000 years ago.

Increased insolation threshold for runaway greenhouse processes on Earth-like planets.

The increase in solar luminosity over geological timescales should warm the Earth's climate, increasing water evaporation, which will in turn enhance the atmospheric greenhouse effect. Above a certain critical insolation, this destabilizing greenhouse feedback can 'run away' until the oceans have completely evaporated. Through increases in stratospheric humidity, warming may also cause evaporative loss of the oceans to space before the runaway greenhouse state occurs. The critical insolation thresholds for these processes, however, remain uncertain because they have so far been evaluated using one-dimensional models that cannot account for the dynamical and cloud feedback effects that are key stabilizing features of the Earth's climate. Here we use a three-dimensional global climate model to show that the insolation threshold for the runaway greenhouse state to occur is about 375 W m(-2), which is significantly higher than previously thought. Our model is specifically developed to quantify the climate response of Earth-like planets to increased insolation in hot and extremely moist atmospheres. In contrast with previous studies, we find that clouds have a destabilizing feedback effect on the long-term warming. However, subsident, unsaturated regions created by the Hadley circulation have a stabilizing effect that is strong enough to shift the runaway greenhouse limit to higher values of insolation than are inferred from one-dimensional models. Furthermore, because of wavelength-dependent radiative effects, the stratosphere remains sufficiently cold and dry to hamper the escape of atmospheric water, even at large fluxes. This has strong implications for the possibility of liquid water existing on Venus early in its history, and extends the size of the habitable zone around other stars.

Geomagnetic disturbances driven by solar activity enhance total and cardiovascular mortality risk in 263 U.S. cities.

BACKGROUND: Short-term geomagnetic disturbances (GMD) driven by the quasi-periodic 11-year cycle of solar activity have been linked to a broad range of adverse health effects, including cardiovascular diseases (CVD) and total deaths. We conducted a large epidemiological study in 263 U.S. cities to assess the effects of GMD on daily deaths of total, CVD, myocardial infarction (MI), and stroke. METHODS: We employed a two-step meta-analysis approach, in which we estimated city-specific and season-stratified mortality risk associated with a GMD parameter (Kp index) in 263 U.S. cities. In addition, sensitivity analysis was performed to assess whether effect modification of particulate matter (PM2.5) in the prior day changed Kp index effects on daily deaths after adjusting for confounders. RESULTS: We found significant association between daily GMD and total, CVD, and MI deaths. The effects were even stronger when we adjusted the models for 24-h PM2.5 for different seasons. For example, in the winter and fall one standard deviation of z-score Kp index increase was associated with a 0.13 and 0.31% increase in total deaths, respectively (Winter: p = 0.01, 95% CI: 0.02 to 0.24; Fall: p = 0.00001; 95% CI: 0.23 to 0.4), without adjusting for PM2.5. The effects of GMD on total deaths were also observed in spring and summer in the models without PM2.5 (p = 0.00001). When the models were adjusted for PM2.5 the total deaths increased 0.47% in winter (p = 0.00001, 95% CI: 0.3 to 0.65) and by 0.23% in fall (p = 0.001, 95% CI: 0.09 to 0.37). The effects of GMD were also significant associated with MI deaths and CVD. No positive significant association were found between Kp and stroke. The GMD effects on deaths were higher than for 24 h-PM2.5 alone, especially in spring and fall. CONCLUSION: Our results suggest that GMD is associated with total, CVD and MI deaths in 263 U. S cities. Increased mortality in the general population during GMD should be further investigated to determine whether those human physiological dynamics driven by variations in solar activity can be related to daily clinical cardiovascular observations.

Extreme phenophase delays and their relationship with natural forcings in Beijing over the past 260 years.

By merging reconstructed phenological series from published articles and observations of China Phenology Observation Network (CPON), the first blooming date of Amygdalus davidiana (FBA) in Beijing between 1741 and 2000 is reconstructed. The Butterworth method is used to remove the multi-year variations for generating the phenological series of annual variations in the first blooming date of A. davidiana. The extreme delay years in the phenological series are identified using the percentage threshold method. The characteristics of the extreme delays and the correspondence of these events with natural forcings are analysed. The main results are as follows. In annual phenological series, the extreme delays appeared in single year as main feature, only A.D.1800-1801, 1816-1817 and 1983-1984 were the events of two consecutively extreme years. Approximately 85% of the extreme delays occurred during 1-2 years after the large volcanic eruptions (VEI ≥ 4) in the eastern rim or the western rim of the Pacific Ocean, as the same proportion of the extreme delays followed El Niño events. About 73% years of the extreme delays fall in the valleys of sunspot cycles or the Dalton minimum period in the year or the previous year. According to the certainty factor (CF), the large eruptions have the greatest influence to the extreme delays; sunspot activity is the second, and ENSO is the last one. The extreme phenological delayed year is most likely to occur after a large eruption, which particularly occurs during El Niño year and its previous several years were in the descending portion or valley of sunspot phase.

The Impact of Ionospheric and Geomagnetic Changes on Mortality from Diseases of the Circulatory System.

We investigate the impact of solar activity changes on mortality from cardiovascular causes of death in the period 1994-2011 in the Czech Republic. This period coincides with the time of solar cycle no. 23 and the surrounding minima when there was an unusually low level of solar activity. We use long-period daily time series of numbers of deaths by cause, solar activity indices (the relative sunspot number, and the intensity of solar radio flux), geomagnetic indices (Kp-the planetary index that indicates the fluctuation rate of horizontal components of the geomagnetic field, the Auroral Electrojet, and the disturbance storm time), and physical parameters describing the ionospheric effects (the critical frequency of the ionospheric F2 layer and the content of free electrons in the ionosphere). The results of the analysis confirm the hypothesis that there is no direct correlation between the geomagnetic solar index, Kp, and the number of deaths from acute myocardial infarction (code I21) or brain stroke (code I64) during the maxima of the solar cycle. On the other hand, the ionospheric parameters explain a greater part of the variability in the number of deaths for acute myocardial infarction or brain stroke than the model with solar parameters. The analysis shows that, because the values are geographically specific, the ionospheric parameters may describe the variability in the number of deaths from cardiovascular causes better than the solar indices. The cardiovascular diseases thus respond to the changes in the solar activity and to abnormal solar events indirectly through a concentration of electrical charges in the earth's environment.

'The sun without a permit': Serbian solar politics, informational risk cascades, and the Great Disappearing Act of August 1999.

In the summer of 1999, the Serbian Ministry of Health issued a public health warning about the environmental risks associated with the total solar eclipse to took place on 11 August. The warning contained a list of phantom symptoms unknown to medical profession. Some of these included severe itching, hypertension, cardiac palpitation and frequent urination. Despite the warning's patent absurdity, the Serbian public widely observed it by seeking indoor and underground shelter from the lunar shadow, participating in what I term a 'great public disappearing act'. By contrast, the rest of Europe and the Middle East embraced the event as a public spectacle, with millions thronging the streets and observation posts. This paper raises two key questions: Why did the Serbian government issue the odd warning? And why did the Serbian public observe it? In contrast to the conventional readings of the event as a compound effect of a political manipulation and a lack of public scientific education, I argue that the public behavior on the eclipse day was a meaningful response to the social, political and environmental circumstances in the worn-torn Serbia. Using insights from the social amplification of risk framework, I demonstrate that the great disappearing act was a paradigmatic example of herd behavior governed by the media-driven informational cascades. I further argue that the actors involved in the production and reproduction of phantom ecliptic risks - doctors, journalists, government officials, ordinary citizens - jointly enhanced their plausibility in a way that eventually eliminated the possibility of any behavior not mediated by the cascading processes of risk production.

Resurrecting Maunder's ghost: John 'Jack' Eddy, the Maunder Minimum, and the rise of a dilettante astrophysicist.

During the 1970s, widespread scientific interest in the risks of climate change prompted John A. Eddy (1931-2009), an astrophysicist with the National Center for Atmospheric Research in Boulder, CO, to investigate whether sunspots could be used to predict future climate changes. Methodologically, Eddy's investigations were uniquely historical in nature. By interrogating old manuscripts of solar observations since the early seventeenth century, he identified what appeared to be a correlation between the so-called Maunder Minimum - a virtual cessation of sunspots between 1645 and 1715 - and severely cold temperatures during the Little Ice Age. While he could not identify the physical mechanisms that governed solar-climate relationships, this historical episode fostered his curiosity. Fortuitously, Eddy's solar-climate research coincided with efforts to use satellites to monitor and record variations in solar energy output, which in context constituted a significant development in managing environmental and technological risk. But using the Maunder Minimum to advance the frontiers of knowledge about solar-terrestrial relationships was not Eddy's only - or even primary - motivation. In the mid-1840s, German astronomer Heinrich Schwabe (1789-1875) discovered what appeared to be a decadal sunspot cycle, the existence of which inspired generations of astrophysicists to more precisely estimate its length as well as determine its underlying causes. Eddy, however, came to believe that the astronomical community failed to consider the implications of subsequent evidence suggesting that Schwabe's solar cycle was not an enduring characteristic of the sun. Instead, he reasoned that evidence offered by nineteenth-century European astronomers Gustav Sporer and Edward Maunder in the 1880s and 1890s had been entirely overlooked. But rather than arguing that their evidence was overlooked in error, Eddy identified what he cast as a conspiracy of wilful ignorance on the part of a staid and conservative astronomical community. By utilizing Eddy's private hand-written notes as they appeared in undergraduate lectures, public speeches and academic talks, as well as his appreciation for the seminal views of sociologist of science Thomas Kuhn, I show that Eddy sought to rectify this injustice by proposing a contrasting vision of science as an interdisciplinary, collaborative and creative process of exploring the ignored areas between scientific disciplines.