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Signature of the 27-day variation in hemispheric sunspot activity and asymmetry during 2010-2015

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Research in Astronomy and Astrophysics 2021年第4期21卷 331-340页

作者： Prithvi Raj Singh Ahmad Islam Saad Farid Tarun Kumar Pant Abhay Kumar Singh Department of Physics Banaras Hindu UniversityVaranasi-221005India Physics and Chemistry Department Faculty of EducationAlexandria UniversityAlexandria-21526Egypt Space Physics Laboratory VSSCThiruvananthapuram-695022India

In the present work,we study the time evolution,significance of the N-S asymmetry excesses presented as a function of the solar cycle and prominent rotational periods(~27 d)separately for the northern and southern *** have investigated short-term variations of the hemispheric solar activity(sunspot numbers and sunspot areas)during the time period 2010-2015,which covers the ascending and the maximum phase of solar cycle *** have implemented the Lomb-Scargle periodogram and continuous wavelet transform power spectrum techniques to study the time evolution and dominant rotational periods separately for the northern and southern hemispheres,and whole solar *** results showed that the northern hemisphere exhibited longer solar synodic periods than the southern hemisphere,indicating that the northern hemisphere has a lower rotation ***,the northern hemisphere was found to be dominant before transferring to the southern hemisphere during ***,the sunspot areas clearly demonstrated a two-peak structure of solar activity in the northern and southern hemispheres respectively during 2012 and *** statistical significance of the southern hemisphere affirmed enhanced excess during the maximum phase of solar cycle 24.

关键词： Sunspots Sunspot Area Asymmetry solar cycle

Relationship between air temperature oscillations and solar variability on short and medium time scales

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Science China Earth Sciences 2011年第6期54卷 912-923页

作者： YANG ChunXia WU HongFa HU DanTing Institute of Information and System Science Nanjing University of Information Science and Technology Nanjing 210044 China

The contemporary science of climate change is increasingly focusing on the temporal and spatial characteristics of temperature oscillations and determining possible underlying *** particular,the effect of variations in solar irradiance on the variability of the climate remains a hot topic of *** studies focus on the effects of solar variation on the Earth's climate on long time *** study presents the responses of regional climates to solar variations on shorter time scales using two datasets:one for the air temperature in Nanjing and the Greenwich sunspot number,and the other for the air temperature in Shijiazhuang and the United States sunspot *** empirical mode decomposition,both the 11-year quasi-period of the sunspot number and similar periods including approximately 5.5-and 10.5-year cycles of the air temperature in Nanjing and Shijiazhuang are ***,correlation analysis of similar periodic components for the sunspot number and air temperature indicates that changes in the air temperature on short and medium time scales are not linked to solar *** is further confirmed by a test of whether a mode component is a stochastic noise *** shorter periods are also found at the 95% confidence level;in particular,the 3.1-year period of the Nanjing air temperature coincides with a previously obtained empirical ***,no temperature variations on shorter time scales correlate with solar variability.

关键词： climate change temperature multi-scale variations solar cycle

The variation of the estimated GPS instrumental bias and its possible connection with ionospheric variability

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Science China(Technological Sciences) 2014年第1期57卷 67-79页

作者： ZHANG DongHe SHI Hao JIN YaQi ZHANG Wei HAO YongQiang XIAO Zuo Department of Geophysics Peking University Department of Geodesy and Geomatics Engineering University of New Brunswick Fredericton 4400 New Brunswick Canada

Based on the analysis of the satellite DCB data estimated by our method and the Center for Orbit Determination in Europe(CODE)from 1999 to 2011,the features of the temporal variation of differential code biases(DCB)are ***,there are three types of variations in DCB on different time *** first one is the day-to-day variation that exhibits more obviously in solar maximum *** second one is the variation with about one year periodic variation that behaves more obviously from 1999 to *** last one is the monotonously descending tendency from 1999 to *** the basic ionospheric approximation in DCB estimation method,the features of the variability of the ionospheric morphology from 1999to 2010 are also displayed based on the ionospheric characteristic *** can be concluded that the day-to-day and annual variation of the estimated global positioning system(GPS).DCB is related to the ionospheric *** variation of DCBs on solar cycle time scale includes the real hardware DCBs and pseudo-DCBs induced by ionospheric *** doubt,these kinds of"pseudo"variations of DCB will affect the precision of ionospheric total electron content(TEC)derived from the GPS *** addition,this study is helpful for evaluating the influence of ionospheric weather on TEC derivation and is also useful for developing one estimation method of DCB with more stability and precision through introducing a more practical ionospheric model.

关键词： DCB ionospheric variability GPS instrumental bias solar cycle

Recent Progresses on Ionospheric Climatology Investigations

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空间科学学报 2012年第5期32卷 665-680页

作者： LIU Libo WAN Weixing CHEN Yiding LE Huijun ZHAO Biqiang (Beijing National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029

The ionosphere varies over multiple time scales,which are classified into two categories: the climatology and weather *** this national report,we give a brief summary of recent progresses in ionospheric climatology with focus on(1) the seasonal variations,(2) solar cycle effects, and(3) empirical modeling of the *** seasonal variations of the ionosphere have been explored in many works to give a more detailed picture with regional and global features at various altitudes by analyzing the observation data from various sources and ***,a series of studies reported the response of the ionosphere to solar cycle variations,which revealed some novel and detailed features of solar activity dependence of ionospheric parameters at different altitudes. These investigations have improved our understanding on the states of the ionosphere and underlying fundamental processes,provided clues to future studies on ionospheric weather,and guided ionospheric modeling,forecasting and related applications.

关键词： Ionosphere Climatological variation Seasonal variations solar cycle Ionospheric modeling

Amplification of the solar Signal in the Summer Monsoon Rainband in China by Synergistic Actions of Different Dynamical Responses

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Journal of Meteorological Research 2017年第1期31卷 61-72页

作者： Liang ZHAO Jingsong WANG Haiwen LIU Ziniu XIAO State Key Laboratory of Numerical Modeling for Atmosphere Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 National Climate Center China Meteorological Administration Beijing 100081 China National Center for Space Weather Beijing 100081 Department of Aviation Meteorology Civil Aviation University of China Tianjin 300300

A rainband meridional shift index （RMSI） is defined and used to statistically prove that the East Asian summer monsoon rainband is usually significantly more northward in the early summer of solar maximum years than that of solar minimum years. By applying continuous wavelet transform, cross wavelet transform, and wavelet coherence, it is found that throughout most of the 20th century, the significant decadal oscillations of sunspot number （SSN） and the RMSI are phase-locked and since the 1960s, the SSN has led the RMSI slightly by approximately 1.4 yr. Wind and Eliassen-Palm （EP） flux analysis shows that the decadal meridional oscillation of the June rainband likely re- sults from both a stronger or earlier onset of the tropical monsoon and poleward shift of the subtropical westerly jet in high-solar months of May and June. The dynamical responses of the lower tropical monsoon and the upper subtropical westerly jet to the 11-yr solar cycle transmit bottom-up and top-down solar signals, respectively, and the synergistic actions between the monsoon and the jet likely amplify the solar signal at the northern boundary of the monsoon to some extent.

关键词： solar cycle rainband East Asian summer monsoon decadal variability EP flux precipitation

Bad News—The Dominant Causes of the Earth’s Global Warming Are Processes on the Sun, and Humanity Can Do Nothing or Little to Stop It?

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第4期10卷 1388-1411页

作者： Nikolay Petrov Takuchev Trakia University Stara Zagora Bulgaria

Arguments that global warming in the Earth’s atmosphere of the last 70 years is partially or entirely caused by changes in the solar magnetic field are presented in the work. Global warming is probably a consequence of ionizing radiation emitted from the Sun mainly in the “rise” phase of solar activity. The ionizing radiation is positively charged particles with high energy. They penetrate deep into the Earth’s atmosphere, creating increased content of ions serving as condensation nuclei. The condensation nuclei increase cloudiness in the lower atmosphere and lower the surface air temperature. When solar activity decreases as observed in the last 70 years, the reverse process occurs— cloud cover decreases, more solar electromagnetic radiation reaches the earth’s surface and increases the temperature. An additional argument for the presence of high-energy radiation that penetrates deeply into the Earth’s atmosphere and even reaches the Earth’s surface is the high statistically significant correlation between the fluxes of such radiation recorded by GOES series satellites in a geostationary orbit (36,000 km above the Earth’s surface) and the human mortality from deadliest diseases.

关键词： Global Warming Climate Change solar cycle Ionizing Radiation Satellite Data

Temporal Distribution of Total Column Ozone over Cochin—A Study Based on in Situ Measurements and ECMWF Reanalysis

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Open Journal of Marine Science 2016年第2期6卷 200-209页

作者： Vazhathottathil Madhu Karthika Gangadharan Department of Atmospheric Sciences School of Marine Sciences Cochin University of Science and Technology Cochin India

The variability of Atmospheric ozone is very important to understand the radiative balance of the earth-atmospheric system and climate change. In order to understand the temporal variability of total column ozone (TCO) over the coastal station Cochin (9.95°N, 76.27°E), we used the ECMWF (European Centre for Medium-Range Weather Forecasts) reanalysis TCO and ground based measurements using Microtop II Sun Photometer (Ozonometer). The trend, seasonal changes and diurnal variation of ozone concentration have been studied in detail for the period 1981-2014. Cochin is a tropical coastal station with tropical monsoon climate and hence we examined the variability of TCO during pre-monsoon (March-May), monsoon (June-September) and post monsoon (October-December) seasons. Significant variations are noted in the TCO for the different seasons during the period of study. Based on the measurements and analysis, it is observed that TCO is maximum during monsoon and minimum during pre- and post-monsoon. We computed the TCO climatology for pre-monsoon (262.0 DU), monsoon (275 DU) and post-monsoon (253 DU) seasons and found that TCO shows a decadal trend (solar cycle). During monsoon season TCO varies with an increase of approximately 14 DU from the pre-monsoon value and a decrease of 22 DU from the post-monsoon value. The increase in TCO concentration during monsoon may be attributed to the monsoonal wind circulations and organized convection. The validation of ECMWF TCO with in situ measurements using Microtop II Ozonometer has been carried out for the year 2015 and found that the values are positively correlated. The diurnal variability of TCO was examined for vernal and autumnal equinox days and noticed the change in variability.

关键词： Total Column Ozone (TCO) solar cycle Seasonal Variability Quasi-Biennial Oscillation

The Dependence between solar Flare Emergence and the Average Background solar X-Ray Flux Emission

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International Journal of Astronomy and Astrophysics 2024年第3期14卷 149-161页

作者： Yael Peleg Rami Babayew Itzhak Orion Nuclear Engineering Unit Ben Gurion University of the Negev Beer Sheva Israel

solar flares, sudden bursts of intense electromagnetic radiation from the Sun, can significantly disrupt technological infrastructure, including communication and navigation satellites. To mitigate these risks, accurate forecasting of solar activity is crucial. This study investigates the potential of the Sun’s background X-ray flux as a tool for predicting solar flares. We analyzed data collected by solar telescopes and satellites between the years 2013 and 2023, focusing on the duration, frequency, and intensity of solar flares. We compared these characteristics with the background X-ray flux at the time of each flare event. Our analysis employed statistical methods to identify potential correlations between these solar phenomena. The key finding of this study reveals a significant positive correlation between solar flare activity and the Sun’s background X-ray flux. This suggests that these phenomena are interconnected within the framework of overall solar activity. We observed a clear trend: periods with increased occurrences of solar flares coincided with elevated background flux levels. This finding has the potential to improve solar activity forecasting. By monitoring background flux variations, we may be able to develop a more effective early warning system for potentially disruptive solar flares. This research contributes to a deeper understanding of the complex relationship between solar flares and the Sun’s overall radiative output. These findings indicate that lower-resolution X-ray sensors can be a valuable tool for identifying periods of increased solar activity by allowing us to monitor background flux variations. A more affordable approach to solar activity monitoring is advised.

关键词： Space Weather solar Flare solar Activity Sunspots solar cycle

Recent Progresses on Ionospheric Climatology Investigations

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Recent Progresses on Ionospheric Climatology Investigations