Temporal variations of different solar activity indices through the solar cycles 21-23

Göker, Ümit Deniz; Singh, Jagdev; Nutku, Ferhat; Priyal, Muthu

doi:10.2298/saj1795059g

Cited by 4 publications

(7 citation statements)

References 10 publications

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“…9). As the contribution to plage areas, radio flux, TSI or disk-integrated magnetic flux density is dominated by these large ARs, no significant suppression of Cycle 23 is detected in these proxies either (Göker et al 2017).…”

Section: External Empirical Precursorsmentioning

confidence: 86%

Solar cycle prediction

Petrovay

2020

Living Rev Sol Phys

194

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A review of solar cycle prediction methods and their performance is given, including early forecasts for Cycle 25. The review focuses on those aspects of the solar cycle prediction problem that have a bearing on dynamo theory. The scope of the review is further restricted to the issue of predicting the amplitude (and optionally the epoch) of an upcoming solar maximum no later than right after the start of the given cycle. Prediction methods form three main groups. Precursor methods rely on the value of some measure of solar activity or magnetism at a specified time to predict the amplitude of the following solar maximum. The choice of a good precursor often implies considerable physical insight: indeed, it has become increasingly clear that the transition from purely empirical precursors to model-based methods is continuous. Model-based approaches can be further divided into two groups: predictions based on surface flux transport models and on consistent dynamo models. The implicit assumption of precursor methods is that each numbered solar cycle is a consistent unit in itself, while solar activity seems to consist of a series of much less tightly intercorrelated individual cycles. Extrapolation methods, in contrast, are based on the premise that the physical process giving rise to the sunspot number record is statistically homogeneous, i.e., the mathematical regularities underlying its variations are the same at any point of time, and therefore it lends itself to analysis and forecasting by time series methods. In their overall performance during the course of the last few solar cycles, precursor methods have clearly been superior to extrapolation methods. One method that has This article is a revised version of

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Section: External Empirical Precursorsmentioning

confidence: 86%

Solar cycle prediction

Petrovay

2020

Living Rev Sol Phys

194

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“…(c) In SAC 23, large SGs reach their maximum numbers about 2 years later than the small ones and this time the difference is more effective for the magnetic field than in TSI. Small groups are efficient in TSI after the beginning of 1990 in SAC 22 and in the year 2000 of SAC 23 while large SGs show a double peak both in SACs 22 and 23 for the maximum phases of SACs, and they are dominant after the year 2002 in SAC 23 (Göker et al 2016, see Fig. 2).…”

Section: Data Analysis Results From the Ground-based Telescopesmentioning

confidence: 95%

“…(f) The FA ratio decreases with increasing activity levels, whereas FA shows an increase in the decreasing phase of SAC 23. In the increasing phase of SAC 23, FA starts to increase from 1996 to 2000 because FA correlates with large SGs (Göker et al 2016, see Figs. 3 and 4).…”

Section: Data Analysis Results From the Ground-based Telescopesmentioning

confidence: 95%

“…All small type SGs are lower in SAC 23 as compared to large SGs. Magnetic field is related with small SGs while TSI values are connected with large SGs (Göker et al 2016, see Figs. 1 and 2).…”

Section: Data Analysis Results From the Ground-based Telescopesmentioning

confidence: 97%

“…It is considered that solar irradiance variations both the spectral and total are essentially caused by solar surface magnetism and thermal structures of magnetic features (sunspots, faculae) (Foukal 1992, Chapman et al 1996, Fligge et al 1998, Fligge et al 2000, Krivova et al 2003. Göker et al (2016) examined a statistical analysis of solar activity indices "total solar irradiance (TSI), magnetic field, Ca II K-flux, faculae and plage areas due to the type of sunspots/SGs" through the SACs 21-23 and found interesting results that are connected with the chromospheric ions and SSI data. The main results from that paper are as follows:…”

Section: Data Analysis Results From the Ground-based Telescopesmentioning

confidence: 99%

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Solar spectral irradiance variability of some chromospheric emission lines through the solar activity cycles 21-23

2017

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A study of variations of solar spectral irradiance (SSI) in the wavelength ranges 121.5 nm-300.5 nm for the period 1981-2009 is presented. We used various data for ultraviolet (UV) spectral lines and international sunspot number (ISSN) from interactive data centers such as SME (NSSDC), UARS (GDAAC), SORCE (LISIRD) and SIDC, respectively. We reduced these data by using the MATLAB software package. In this respect, we revealed negative correlations of intensities of UV (289.5 nm-300.5 nm) spectral lines originating in the solar chromosphere with the ISSN index during the unusually prolonged minimum between the solar activity cycles (SACs) 23 and 24. We also compared our results with the variations of solar activity indices obtained by the ground-based telescopes. Therefore, we found that plage regions decrease while facular areas are increasing in SAC 23. However, the decrease in plage regions is seen in small sunspot groups (SGs), contrary to this, these regions in large SGs are comparable to previous SACs or even larger as is also seen in facular areas. Nevertheless, negative correlations between ISSN and SSI data indicate that these variations are in close connection with the classes of sunspots/SGs, faculae and plage regions. Finally, we applied the time series analysis of spectral lines corresponding to the wavelengths 121.5 nm-300.5 nm and made comparisons with the ISSN data. We found an unexpected increase in the 298.5 nm line for the Fe II ion. The variability of Fe II ion 298.5 nm line is in close connection with the facular areas and plage regions, and the sizes of these solar surface indices play an important role for the SSI variability, as well. So, we compared the connection between the sizes of faculae and plage regions, sunspots/SGs, chemical elements and SSI variability. Our future work will be the theoretical study of this connection and developing of a corresponding model.

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Jeomanyetik Fırtınaların Pilotların Kognitif Durumlarına Etkileri Üzerine Hipotez

Göker¹

2018

Savunma Bilimleri Dergisi

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ÖzPilotlar gibi bilişsel (kognitif) yeteneği gelişmiş, hareketlerinde kuvvetli bir kararlılığa sahip ve görevinde ya da tehlikeli durumlarda izleyeceği doğru adımları bilmesi gibi sinirsel uyarımlarını etkileyen tüm bilişsel ve kişilik (personality) psikolojisi testlerinin tamamını başarıyla geçmiş kişilerde organik süreçler kusursuz işlemektedir. Havacılık Psikolojisi, uçuşun uçuş personeli ve yolcular üzerindeki fiziksel ve zihinsel etkileriyle ilgilenen bilim dalıdır. Belli dönemlerde dünya manyetosferinin düzenini bozucu etkiye sahip olan jeomanyetik fırtınalar gibi astronomik olaylar, bu organik süreçler üzerinde halsizlik, keyifsizlik ve sebebi belli olmayan bölgesel baş ağrıları, hareket fonksiyonlarında düzensizlik, denge bozukluğu, kalpte enfarktüs, nöbet durumları ve sinir sistemine bağlı ruhsal bozukluklar gibi negatif etkilere sebep olacaktır. Bu makalede, jeomanyetik fırtınalarla ilgili önceki çalışmaların verdiği sonuçlar ile nörofizyolojik araştırma sonuçlarından yola çıkarak, jeomanyetik fırtınaların etkisinin beyin ve sinir sisteminde yapması beklenen hasarlar belirtilmiştir. Bu etkilerin incelendiği laboratuvarların Türkiye'de kurulması halinde olası yapılabilecek psikolojik ve medikal deneylerin uygulama yöntemleri de makalede ayrıca verilmiştir. Yüksek enlemlerde uçan pilot ve uçuş ekibi, jeomanyetik fırtınanın etkisini birebir yaşayacaktır; hâlbuki Türkiye gibi orta enlemlerde hava taşıtı kullanan pilot ve uçuş ekibinin ancak laboratuvar ortamında test edilerek, bu etkilere verdikleri tepkiler ölçülebilir. Bahsi geçen bu deneylerin havacılık psikolojisi literatüründe ilk kez uygulanacak olması nedeniyle de bu hipotez ayrı bir önem taşımaktadır. AbstractThe organic processes work flawlessly in those who have successfully completed all the tests of cognitive and personality psychology, such as pilots. Pilots with cognitive abilities have a strong commitment to their movements, and they influence their neural stimulation, such as the ability to acknowledge the right steps to follow in their task or in dangerous situations. Aviation Psychology deals with the physical and mental effects of flight on aircrew personnel and passengers. Astronomical events, such as geomagnetic storms that have a disruptive effect on Earth's magnetosphere in certain periods, will cause negative effects, such as weakness, malaise and unspecified regional headaches, irregularity in movement functions, misbalance, heart infarction, seizure situations and mental disorders due to the nervous system, on these organic processes. This article describes the expected damages to the brain and nervous system caused by the effects of geomagnetic storms, based on the results of previous studies on geomagnetic storms and neurophysiological studies. Application methods of the possible psychological and medical experiments in case of the laboratories to be established in Turkey are also given in this article. The pilot and flight crew flying at high latitudes will experience the effect of the geomagnetic storm directly; whereas the res...

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Temporal variations of different solar activity indices through the solar cycles 21-23

Cited by 4 publications

References 10 publications

Solar cycle prediction

Solar cycle prediction

Solar spectral irradiance variability of some chromospheric emission lines through the solar activity cycles 21-23

Jeomanyetik Fırtınaların Pilotların Kognitif Durumlarına Etkileri Üzerine Hipotez

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