The effects of total solar irradiance (TSI) and volcanic activity on long-term global temperature variations during solar cycles 19–23 were studied. It was shown that a large proportion of climate variations can be explained by the mechanism of action of TSI and cosmic rays (CRs) on the state of the lower atmosphere and other meteorological parameters. The role of volcanic signals in the 11-year variations of the Earth’s climate can be expressed as several years of global temperature drop. Conversely, it was shown that the effects of solar, geophysical, and human activity on climate change interact. It was concluded that more detailed investigations of these very complicated relationships are required, in order to be able to understand issues that affect ecosystems on a global scale.
Journal of Advanced Research (2017) 329–332 Contents lists available at ScienceDirect Journal of Advanced Research journal homepage: www.elsevier.com/locate/jare Short Communication Long-term global temperature variations under total solar irradiance, cosmic rays, and volcanic activity Lilia Biktash Department of Solar-Terrestrial Physics, IZMIRAN, Moscow, Troitsk, Russia g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 30 October 2016 Revised 26 February 2017 Accepted March 2017 Available online 14 March 2017 Keywords: Global temperature Total solar irradiance Cosmic rays Volcanic activity a b s t r a c t The effects of total solar irradiance (TSI) and volcanic activity on long-term global temperature variations during solar cycles 19–23 were studied It was shown that a large proportion of climate variations can be explained by the mechanism of action of TSI and cosmic rays (CRs) on the state of the lower atmosphere and other meteorological parameters The role of volcanic signals in the 11-year variations of the Earth’s climate can be expressed as several years of global temperature drop Conversely, it was shown that the effects of solar, geophysical, and human activity on climate change interact It was concluded that more detailed investigations of these very complicated relationships are required, in order to be able to understand issues that affect ecosystems on a global scale Ó 2017 Production and hosting by Elsevier B.V on behalf of Cairo University This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Introduction Numerous investigations carried out recently report apparent climate responses to the 11-year solar cycle, although the Sun’s role for weather and climate remain a matter of controversy Long-term global temperature variations can be exposed to different cosmophysical and geophysical factors It has been suggested that the recent trend of global warming is mainly due to uncon- Peer review under responsibility of Cairo University E-mail address: lilia_biktash@mail.ru trolled industrial activity This trend is leading to irreversible changes in the atmosphere, hydrosphere and biosphere The consequences of this process are also observed in seismic and volcanic activity As hypothesized by Eddy [1], the climate variations might be due to the total solar irradiance Total solar irradiance (TSI) is a measure of the solar energy flux TSI describes the total radiant energy, in the form of electromagnetic radiation emitted by the Sun at all wavelengths, that falls for each second on square meter outside the Earth’s atmosphere, a value proportional to the ‘‘solar constant” introduced earlier in the previous century Lean and Fröhlich [2] show that the radiative flux decreases when dark http://dx.doi.org/10.1016/j.jare.2017.03.002 2090-1232/Ó 2017 Production and hosting by Elsevier B.V on behalf of Cairo University This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) 330 L Biktash / Journal of Advanced Research (2017) 329–332 sunspots are present on the disk, and increases due to bright faculae or plages Fligge and Solanki [3], using a model of the total solar irradiance since 1700, found that long-term TSI variations exist due to the evolution of the solar network and other processes However, these variations are not significant enough to explain climate change, especially on a scale as large as that of global warming Since the discovery of galactic and solar cosmic rays, their influence on the Earth’s climate has been subject to speculation, and now, cosmic ray activity as a possible mechanism affecting climate change is the subject of considerable debate Cosmic rays (CRs) are high energy charged particles, originating in outer space, that travel at nearly the speed of light and strike the Earth from all directions Cosmic rays can be divided into two types: galactic cosmic rays (GCRs) and solar energetic particles (SEPs) GCRs are high energy particles originating outside the solar system, whereas SEPs are high energy particles (predominantly protons) emitted by the Sun, primarily in solar particle events However, the term ‘‘cosmic ray” is often used to refer only to the GCR flux Recent studies by Pudovkin and Raspopov [4], Tinsley [5], and Swensmark [6], have shown that the Earth’s cloud coverage is strongly influenced by cosmic ray intensity Conditions in interplanetary space, which can influence GCRs and climate change, have been studied in numerous works As has been demonstrated by Biktash [7], the long-term CR count rate and global temperature variations in 20–23 solar cycles are modulated by solar activity and by the IMF (interplanetary magnetic field) A possible geophysical factor which is able to affect the influence of solar activity on the Earth’s climate is volcanism The effects of volcanism can lead to serious consequences in the atmosphere and the climate, as shown by Robock [8] A study of solar activity influence on global air–surface temperature with and without volcanic impact is presented by Barlyaeva et al [9] The main findings and mechanisms have implications for the question of where and how the Sun exerts influence on the climate system The purpose of this work is to find out whether there are decadal variations in the Earth’s climate, try to establish their spatial and temporal distribution, and how this distribution comes about The findings will then be used in the important task of finding a possible explanation for the contradictory results presented in literature studies of the impact of solar activity on the Earth’s climate Volcanic signals in the 11-year variations of the Earth’s climate are discussed, with a final proposal suggesting that solar, human and volcanic activity extert a combined effect on the Earth’s climate Data and method The sunspot numbers (SSN), global surface air temperatures (GSAT), TSI, interplanetary magnetic field (IMF), cosmic rays annual means data during solar cycles 19–23 are used for studying long-term air temperature variations The IMF and SSN data were obtained from the OMNI database http://omniweb.gsfc.nasa.gov/ TSI data are used from https://www.ngdc.noaa.gov/ CR data were taken from the Climax (http://ulysses.sr.unh.edu) neutron monitor and annual means of air temperature were obtained from http://data.giss.nasa.gov/gistemp/ The air temperature trend is analyzed by the least square fit to the linear relation y = bx + a, where y is GSAT, x is years of trend study Results and discussion Camp and Tung [10] obtained a global warming signal attributable to the 11-year TSI cycle It was found that there was a globally averaged warming of objectively almost 0.2 K during solar max as compared to solar More importantly, they established that the global-temperature response to the solar cycle is statistically significant at over 95% confidence level The spatial pattern of the warming is of interest, as it shows the polar amplification also expected for the greenhouse effect The statistical significance of such a globally coherent solar response at the surface was established first time by Camp and Tung [10] The result of this paper is open to debate, as several interpretations can be suggested from the graphs and conclusions It should also be noted that the current finding contradicts our previous results [7] Camp and Tung [10] show the detrended temperature variations in K and show ±0.2 K during solar max and solar min, whereas our calculation of detrended GSAT demonstrates ±0.1 °C variations It is important to carry out a secondary analysis to compare results presented before [7,10] The detrended annual means of GSAT variations (denoted as GT) throughout of solar cycles was calculated by the expression GT = 0.016X À 0.11 [7] with the high correlation (R = 0.86) for the trend removal It was shown that the GT variations are very small and their running average changes from +0.1 °C to À0.1 °C during solar cycle 20–23 For these solar cycles, our calculations of SSN, CRs and IMF B (B is module of interplanetary magnetic field) trends not show a significant effect, whilst the GSAT trend is very large, and significant Fig shows the annual variations of SSN (Panel a), GSAT (dashed line in Panel b) and its trend It should be noted that GSAT does not have a trend during solar cycle 19, and varies according the solar cycle Detrended GSAT (thick curve in Fig 1) and its running average variations (solid curve) changes from +0.1 °C to À0.1 °C and is reduced by about 50% compared to Camp and Tung’s results [10] Thus, the relationship of SSN and GT supports the argument that climate variations might be due to the TSI The change in the amount of solar energy entering the lower atmosphere should lead to a change in the temperature of the atmosphere However, there is a large gap between the energy of atmospheric processes and the TSI changes It is now generally accepted that centennial modulation of 11 year TSI driving alone is too small to explain global warming TSI measurements differ widely in experiments, and show unusual behaviour of ultraviolet irradiance during solar cycles For these reasons, the Sun’s role in observed global warming has remained a matter of controversy The disparity of the findings and the lack of established physical mechanisms that could amplify energetically weak TSI variations results in a confusing state of affairs Let us consider, one after another, the effects of TSI, CRs, and volcanic activity in the course of development of solar activity cycles for a clear explanation of the effect on detrended GSAT Fig shows GT (Panel a, dashed curve), and its running average variations (Panel a, solid curve) Annual means of the IMF B and TSI are presented in Panel b; CR variations are presented in Panel c (CLIMAX measurements) It is clearly evident that GT varies accordingly to TSI and opposite to CRs It is apparent that the rising of GT during solar maxima is a result of these processes The physical mechanism of the influence of TSI on GT variations can be represented from Fig as follows As has been pointed out and cited above, the Earth’s atmosphere varies in transparency with the level of solar activity under modulated streams of CRs In these conditions the cloud cover in the atmosphere is decreased during solar maxima and increased during solar minima TSI energy entering to the Earth’s atmosphere owing to CR variations has a different effect on GT, even though TSI is small variated or constant Thus, having established the existence of a solar cycle effect on the main part of climate variations, unequal energy input of TSI to the lower atmosphere can be explained as a result of cloud cover variation during a solar cycle under the variation of the intensity of the cosmic ray fluxes Therefore, enhanced cloud cover in solar acts as gray filter which blocks part of TSI falling on the Earth’s surface and GT is reduced L Biktash / Journal of Advanced Research (2017) 329–332 331 Fig The annual variations of SSN (Panel a), GSAT (dashed line in Panel b), detrended GSAT (denoted as GT) and its running average variations (the solid curve in Panel b) Fig Detrended GSAT denoted as GT – Panel a – the dashed curve, and its running average variations – the solid curve in Panel a; annual means of IMF B and TSI in Panel b; CR CLIMAX variations in Panel c There are 1–2 years of global temperature depressions about 0.1 °C as shown in Fig A possible factor that could explain these temperature depressions is volcanism The effect of volcanism on climate can be very strong, and can lead to serious consequences in the atmosphere and the climate, as shown by Robock [8] One can see that the dates of the largest volcanic activity are associated with the descending phases of the solar cycles, as was noted by Barlyaeva [11] Large volcanic events are shown in Fig by trian- gles: – Fuego, – El Chichon, – Pinatubo, – Ulawun, – Manam These events can be seen in many studies where volcanic activity is presented [9,11] The main trigger mechanism of volcanic activity can be recurrent magnetic activity Long-lasting, recurrent magnetic storms are produced by the joint action of the interplanetary magnetic field and solar wind velocity They can exert primary control over processes in the terrestrial core and give rise to seismic or volcanic activity This subject is under 332 L Biktash / Journal of Advanced Research (2017) 329–332 discussion in the Journal for New Concepts in Global Tectonics Fig shows that the IMF B maxima are shifted to TSI maxima and are close to the declining phases of SC Therefore, several years of global temperature drop can firstly be attributed to TSI variations, and then to volcanic signals that are also can be related to geomagnetic activity In this case, global temperature is increased as result of an increase in the atmosphere’s transparency and acts in opposition to volcanic activity Thus, there are combined effects of solar, CRs, volcanic and human activity on climate change Conclusions The results presented above permit the following conclusions: a large proportion of climate variations can be explained by the action of TSI and CR action on the state of the lower atmosphere and meteorological parameters The trends of SSN, CRs, and IMF B for 20–23 solar cycles not show a significant effect, whilst the GSAT trend is very large, and significant This is a forcible argument to attribute GSAT trend to human activity The role of volcanic signals in the 11-year variations of the Earth’s climate can expressed as several years of global temperature drop This suggests that there are combined effects of solar, cosmic rays, geophysical and human activity on climate change patterns It should be noted that more detailed investigations of such complex interactions are necessary Conflict of interest The authors have declared no conflict of interest Compliance with Ethics Requirements This article does not contain any studies with human or animal subjects Acknowledgments The author is very thankful to the referee for useful remarks and the careful analysis of my paper References [1] Eddy JA The maunder minimum Science 1976;192:1189–202 [2] Lean J, Fröhlich C Solar total irradiance variations In: Blasubramaniam K, Harvey J, Rabin D, editors Synoptic solar physics ASP Conference Series, vol 140 p 281–92 [3] Fligge M, Solanki SK The solar spectral irradiance since 1700 Geophys Res Lett 2000;27(14):2157–60 [4] Pudovkin MI, Raspopov OM The mechanism of action of solar activity on the state of the lower atmosphere and meteorological parameters (a review) Geomagn Aeron 1992;32:593–608 [5] Tinsley BA Influence of solar wind on the global electric circuit, and inferred effects on cloud microphysics, temperature, and dynamics in the troposphere Space Sci Rev 2000;94:231–58 [6] Swensmark H Cosmic rays and Earth’s climate Space Sci Rev 2000;93:175–85 [7] Biktash LZ Evolution of Dst index, cosmic rays and global temperature during solar cycles 20–23 Adv Space Res 2014;54:2525–31 [8] Robock A Volcanic eruptions and climate Rev Geophys 2000;38:191–219 [9] Barlyaeva TV, Mironova IA, Ponyavin DI Nature of decade variations in the climatic data of the second half of the 20th century Doklady Earth Sci 2009;425A:419–23 [10] Camp ChD, Tung KK Surface warming by the solar cycle as revealed by the composite mean difference projection Geophys Res Lett 2007;34:L14703 [11] Barlyaeva TV External forcing on air-surface temperature: geographical distribution of sensitive climate zones J Atmos Solar Terr Phys 2013;94:81–92 ... demonstrated by Biktash [7], the long-term CR count rate and global temperature variations in 20–23 solar cycles are modulated by solar activity and by the IMF (interplanetary magnetic field) A possible... impact of solar activity on the Earth’s climate Volcanic signals in the 11-year variations of the Earth’s climate are discussed, with a final proposal suggesting that solar, human and volcanic activity. .. warming Since the discovery of galactic and solar cosmic rays, their influence on the Earth’s climate has been subject to speculation, and now, cosmic ray activity as a possible mechanism affecting