scholarly journals Millennial Oscillations of Solar Irradiance and Magnetic Field in 600–2600

2021 ◽  
Author(s):  
Valentina Zharkova
Keyword(s):  
Magnetic Field ◽  
Solar Irradiance ◽  
Solar Magnetic Field ◽  
Total Solar Irradiance ◽  
Inertial Motion ◽  
Solar Forcing ◽  
Terrestrial Atmosphere ◽  
Daily Variations ◽  
Spring Equinox

Daily ephemeris of Sun-Earth distances in two millennia (600–2600) showed significant decreases in February–June by up to 0.005 au in millennium M1 (600–1600) and 0.011au in millennium M2 (1600–2600). The Earth’s aphelion in M2 is shorter because shifted towards mid-July and longer because shifted to mid January naturally explaining two-millennial variations (Hallstatt’s cycle) of the baseline solar magnetic field measured from Earth. The S-E distance variations are shown imposed by shifts of Sun’s position towards the spring equinox imposed by the gravitation of large planets, or solar inertial motion (SIM). Daily variations of total solar irradiance (TSI) calculated with these S-E distances revealed TSI increases in February–June by up to 10–12 W / m 2 in M1 and 14–18 W / m 2 in M2. There is also positive imbalance detected in the annual TSI magnitudes deposited to Earth in millennium M2 compared to millennium M1: up to 1.3 W / m 2 , for monthly, and up to 20–25 W / m 2 for daily TSI magnitudes. This imbalance confirms an ascending phase of the current TSI (Hallstatt’s) cycle in M2. The consequences for terrestrial atmosphere of this additional solar forcing induced by the annual TSI imbalances are evaluated. The implications of extra solar forcing for two modern grand solar minima in M2 are also discussed.

Millennial solar irradiance forcing (Hallstatt’s cycle) in the terrestrial temperature variations

2020 ◽  
Author(s):  
Valentina Zharkova ◽  
Simon Shepherd ◽  
Elena Popova
Keyword(s):  
Magnetic Field ◽  
Solar Irradiance ◽  
Principal Component ◽  
Total Solar Irradiance ◽  
Maunder Minimum ◽  
The Sun ◽  
Inertial Motion ◽  
Temperature Variations ◽  
Background Magnetic Field ◽  
Baseline Temperature

<p>In this paper we explore the millennial oscillations (or Hallstatt cycle) of the baseline solar magnetic field, total solar irradiance and baseline terrestrial temperature detected from Principal Component Analysis of the observed solar background magnetic field. We confirm the existence of these oscillations with a period of 2100-2200 years with the similar oscillations detected in carbon 14C isotope abundances and with wavelet analysis of solar irradiance in the past 12 millennia indicating the presence of this  millennial period among a few others. We also test again the idea expressed in our paper Zharkova et al, 2019 that solar inertial motion (SIM) can cause these millennial variations because of a change of the distance between the Sun and Earth. In this paper we use the S-E distance derived from the current JPL ephemeris, finding that currently starting from the Maunder minimum the Sun-Earth  distance is reducing by 0.00025 au per 100 years, or by 0.0025 au per 1000 years.. We present the estimation of variations of solar irradiance caused by this variation of the S-E distance caused by solar inertial motion (SIM) demonstrating these variations to be closely comparable with the observed variations of the solar irradiance measured by the SATIRE payload. We also estimate the baseline temperature variations since Maunder Minimum caused by the increase of solar irradiance caused by the recovery from grand solar minimum and by reduction of the S-E distance caused by  SIM. These estimations show that the Sun will still continue moving towards the Earth in the next 700 years that will result in the increase of the baseline terrestrial temperature by up to 2.5◦C in 2700. These variations of solar irradiance will be over-imposed by the variations of solar activity of 11 cycles and the two grand solar minima occurring in 2020-2053 and 2370-2415 caused by the double dynamo actions inside the Sun.</p>

scholarly journals The periodic variation of 6.7 days for total solar radiation

2009 ◽  
Vol 5 (S264) ◽  
pp. 84-86
Author(s):  
W. Q. Gan ◽  
Y. P. Li
Keyword(s):  
Magnetic Field ◽  
Solar Radiation ◽  
Power Spectrum ◽  
Solar Irradiance ◽  
Solar Magnetic Field ◽  
Solar Rotation ◽  
Periodic Variation ◽  
Total Solar Irradiance ◽  
Total Solar Radiation ◽  
Total Irradiance

AbstractAnalyzing the power spectrum of Total Solar Irradiance (TSI) for the period from 2003 February 25 to 2009 July 6, observed with the Total Irradiance Monitor (TIM) onboard SOlar Radiation and Climate Experiment (SORCE), we found that there are quite a number of periodic variations. The outstanding shortest one is the period of 6.7 days, about one fourth of the period of solar rotation. Checking the solar magnetic field for the same period of time observed with MDI onboard SOHO, we found that there is about 90 degree difference in longitude for the distribution of solar magnetic field. We therefore conclude that both the 90 degree difference in longitude for the distribution of solar magnetic field and the solar rotation are the reason resulting in the periodic variation of 6.7 days for the total solar radiation.

scholarly journals Changes in the Total Solar Irradiance and climatic effects

2021 ◽  
Vol 11 ◽  
pp. 40
Author(s):  
Werner K. Schmutz
Keyword(s):  
Solar Irradiance ◽  
Total Solar Irradiance ◽  
Cold Climate ◽  
Global Temperature ◽  
Ice Age ◽  
Large Temperature ◽  
List Type ◽  
The Sun ◽  
Solar Forcing ◽  
Direct Forcing

The correlation between the averaged reconstructed March temperature record for Kyoto, Japan, and the reconstructed Total Solar Irradiance (TSI) irradiance over 660 years from 1230 to 1890 gives evidence with 98% probability that the Little Ice Age with four cold periods is forced by variations of TSI. If the correlation is restricted to the period 1650–1890, with two cold periods in the 17th and 19th century and for which two independent reconstructed March temperature records are available, the probability of solar forcing increases to 99.99%. As solar irradiance variations have a global effect there has to be a global climatic solar forcing impact. However, by how much global temperature were lower during these minima and with what amplitude TSI was varying is not accurately known. The two quantities, global temperature and TSI, are linked by the energy equilibrium equation for the Earth system. The derivation of this equation with respect to a variation of the solar irradiance has two terms: A direct forcing term, which can be derived analytically and quantified accurately from the Stefan-Boltzmann law, and a second term, describing indirect influences on the surface temperature. If a small TSI variation should force a large temperature variation, then it has to be the second indirect term that strongly amplifies the effect of the direct forcing. The current knowledge is summarized by three statements:During the minima periods in the 13th, 15/16th, 17th, and 19th centuries the terrestrial climate was colder by 0.5–1.5 °C;Indirect Top-down and Bottom-up mechanisms do not amplify direct forcing by a large amount, i.e. indirect solar forcing is of the same magnitude (or smaller) as direct solar forcing;The radiative output of the Sun cannot be lower by more than 2 Wm−2 below the measured present-day TSI value during solar cycle minimum.These three statements contradict each other and it is concluded that at least one is not correct. Which one is a wrong statement is presently not known conclusively. It is argued that it is the third statement and it is speculated that over centennial time scales the Sun might vary its radiance significantly more than observed so far during the last 40 years of space TSI measurements. To produce Maunder minimum type cold climate excursions, a TSI decrease of the order of 10 Wm−2 is advocated.

Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature. II. Different reconstructions of the total solar irradiance variation and dependence on response time scale

2008 ◽  
Vol 464 (2094) ◽  
pp. 1367-1385 ◽  
Author(s):  
Mike Lockwood ◽  
Claus Fröhlich
Keyword(s):  
Solar Irradiance ◽  
Climate Models ◽  
Full Range ◽  
Cosmic Ray ◽  
Total Solar Irradiance ◽  
Data Series ◽  
Solar Forcing ◽  
Time Constants ◽  
The Past ◽  
Published Evidence

We have previously placed the solar contribution to recent global warming in context using observations and without recourse to climate models. It was shown that all solar forcings of climate have declined since 1987. The present paper extends that analysis to include the effects of the various time constants with which the Earth's climate system might react to solar forcing. The solar input waveform over the past 100 years is defined using observed and inferred galactic cosmic ray fluxes, valid for either a direct effect of cosmic rays on climate or an effect via their known correlation with total solar irradiance (TSI), or for a combination of the two. The implications, and the relative merits, of the various TSI composite data series are discussed and independent tests reveal that the PMOD composite used in our previous paper is the most realistic. Use of the ACRIM composite, which shows a rise in TSI over recent decades, is shown to be inconsistent with most published evidence for solar influences on pre-industrial climate. The conclusions of our previous paper, that solar forcing has declined over the past 20 years while surface air temperatures have continued to rise, are shown to apply for the full range of potential time constants for the climate response to the variations in the solar forcings.

scholarly journals Revised historical solar irradiance forcing

2018 ◽  
Vol 615 ◽  
pp. A85 ◽  
Author(s):  
T. Egorova ◽  
W. Schmutz ◽  
E. Rozanov ◽  
A. I. Shapiro ◽  
I. Usoskin ◽  
...  
Keyword(s):  
Solar Irradiance ◽  
Spectral Synthesis ◽  
Total Solar Irradiance ◽  
Magnetic Activity ◽  
Maunder Minimum ◽  
Solar Modulation ◽  
Solar Forcing ◽  
Quiet Sun ◽  
Solar Magnetic Activity ◽  
Spectral Solar Irradiance

Context. There is no consensus on the amplitude of historical solar forcing. The estimated magnitude of the total solar irradiance (TSI) difference between the Maunder minimum and the present time ranges from 0.1 to 6 W m−2 making the simulation of the past and future climate uncertain. One reason for this disagreement is the applied evolution of the quiet Sun brightness in solar irradiance reconstruction models. This work addresses the role of the quiet Sun model choice and updated solar magnetic activity proxies on the solar forcing reconstruction. Aims. We aim to establish a plausible range for the solar irradiance variability on decadal to millennial timescales. Methods. The spectral solar irradiance (SSI) is calculated as a weighted sum of the contributions from sunspot umbra, sunspot penumbra, faculae, and quiet Sun, which are pre-calculated with the NLTE Spectral SYnthesis code (NESSY). We introduce activity belts of the contributions from sunspots and faculae and a new structure model for the quietest state of the Sun. We assume that the brightness of the quiet Sun varies in time proportionally to the secular (22-yr smoothed) variation of the solar modulation potential. Results. A new reconstruction of the TSI and SSI covering the period 6000 BCE - 2015 CE is presented. The model simulates solar irradiance variability during the satellite era well. The TSI change between the Maunder and recent minima ranges between 3.7 and 4.5 W m−2 depending on the applied solar modulation potential. The implementation of a new quietest Sun model reduces, by approximately a factor of two, the relative solar forcing compared to the largest previous estimation, while the application of an updated solar modulation potential increases the forcing difference between the Maunder minimum and the present by 25–40%.

scholarly journals Photometric Observations of the Sun

1994 ◽  
Vol 143 ◽  
pp. 117-129
Author(s):  
Gary A. Chapman
Keyword(s):  
Time Scales ◽  
Solar Irradiance ◽  
Broad Band ◽  
Total Solar Irradiance ◽  
Early Years ◽  
Solar Variability ◽  
The Sun ◽  
Terrestrial Atmosphere ◽  
Photometric Observations ◽  
Disparate Data

Ground-based calorimetry and photometry of the Sun have been carried out for many years. Following the early years, ground-based photometry has largely replaced ground-based calorimetry, in part due to the advent of airborne and spaceborne detector systems for the broad-band measurement of the solar irradiance and the realization of the difficulty of correcting calorimetry measurements for the effects of the terrestrial atmosphere. Even from spacecraft, recent measurements of the total solar irradiance range from about 1367 to 1374 W/m2. Most of this difference can be ascribed to differences in instrumental scales, while a variation of about 1 to 2 W/m2 appears to be due to solar variability. The quiet Sun may also change, globally, over longer time scales. Using disparate data to understand solar variability will require cooperation between a number of current groups, supported by various governments, covering several zones of longitude.

scholarly journals Solar Irradiance Variations: Theory

1998 ◽  
Vol 185 ◽  
pp. 103-109
Author(s):  
H.C. Spruit
Keyword(s):  
Magnetic Field ◽  
Solar Irradiance ◽  
Solar Magnetic Field ◽  
Thermal Response ◽  
Convective Envelope ◽  
New Developments

The following is a somewhat condensed version of discussions previously given elsewhere (Spruit, 1991, 1992). Some new developments not discussed there are presented in sections 4 and 5.Since the observed irradiance variations are so clearly associated with manifestations of the solar magnetic field, I focus here on magnetic causes. Much of the physics of irradiance variations, however, is governed by the thermal response of the convective envelope and this response is similar for other possible causes of irradiance variations.

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