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Solar effects on the Earth/Climate

Discussion in 'Daily & Chat' started by bd7, Jul 16, 2019.

  1. bd7

    bd7 Hard Yards

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    A Formula for the Start of a New Sunspot Cycle: Patrick Geryl

    It is known that the solar radio flux is strongly correlated to the sunspot cycle, but never the less, there is currently no valid formula to calculate the sunspot number from the solar flux. However, we know that the flux is nearly the same at every minimum. If 64 is taken as the low for all cycles, then we can calculate the smoothed proxy sunspot number from the flux, and vice versa. Furthermore, we find a precursor and marker for the start of sunspot cycle 25: The range between October 2018 and February 2019. https://www.researchgate.net/publication/331063430_A_Formula_for_the_Start_of_a_New_Sunspot_Cycle
     
  2. crikey

    crikey Addicted

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    I suggest putting this thread in the bear pit ...bd7
    It has a better chance of survival
     
  3. Claude Cat

    Claude Cat On my bike Moderator Ski Pass: Platinum

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    Lets see how it goes. Easy enough to move if needed.
    Actually I see nothing too controversial about the topic TBH.
     
    Sandy likes this.
  4. bd7

    bd7 Hard Yards

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    Solar wind‐driven geopotential height anomalies originate in the Antarctic lower troposphere

    Lam, Chisham & Freeman

    Abstract
    We use National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data to estimate the altitude and time lag dependence of the correlation between the interplanetary magnetic field component, By, and the geopotential height anomaly above Antarctica. The correlation is most statistically significant within the troposphere. The peak in the correlation occurs at greater time lags at the tropopause (∼6–8 days) and in the midtroposphere (∼4 days) than in the lower troposphere (∼1 day). This supports a mechanism involving the action of the global atmospheric electric circuit, modified by variations in the solar wind, on lower tropospheric clouds. The increase in time lag with increasing altitude is consistent with the upward propagation by conventional atmospheric processes of the solar wind‐induced variability in the lower troposphere. This is in contrast to the downward propagation of atmospheric effects to the lower troposphere from the stratosphere due to solar variability‐driven mechanisms involving ultraviolet radiation or energetic particle precipitation.

    1 Introduction
    Meteorological effects resulting from fluctuations in the solar wind are presently poorly represented in atmospheric models. Indeed, the role of the Sun is one of the largest unknowns in the climate system [Le Treut et al., 2

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GL061421
     
  5. crikey

    crikey Addicted

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    Gee @bd7 you have sent me to do some homework. Its about time l brushed out the cobwebs on this topic. I haven't been into it for awhile
    I do know that there are disagreements amongst researchers,on the start of this new cycle 25.

    What is solar radio flux?
    The solar radio flux at 10.7 cm (2800 MHz) is an excellent indicator of solar activity. Often called the F10.7 index, it is one of the longest running records of solar activity. The F10.7 radio emissions originates high in the chromosphere and low in the corona of the solar atmosphere.
    F10.7 cm Radio Emissions | NOAA / NWS Space Weather Prediction ...

    https://www.swpc.noaa.gov/phenomena/f107-cm-radio-emissions


     
  6. crikey

    crikey Addicted

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    'Actually I see nothing too controversial about the topic'..

    You have been at ski.com too long..@claudecat.,Its a mine field.
     
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  7. bd7

    bd7 Hard Yards

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    LETTER • THE FOLLOWING ARTICLE IS OPEN ACCESS
    The impact of a future solar minimum on climate change projections in the Northern Hemisphere
    G Chiodo1,8, R García-Herrera1,2, N Calvo1, J M Vaquero3, J A Añel4,5, D Barriopedro1,2 and K Matthes6,7

    Published 7 March 2016 • © 2016 IOP Publishing Ltd
    Environmental Research Letters, Volume 11, Number 3
    Abstract

    Solar variability represents a source of uncertainty in the future forcings used in climate model simulations. Current knowledge indicates that a descent of solar activity into an extended minimum state is a possible scenario. With aid of experiments from a state-of-the-art Earth system model,we investigate the impact of a future solar minimum on Northern Hemisphere climate change projections. This scenario is constructed from recent 11 year solar-cycle minima of the solar spectral irradiance, and is therefore more conservative than the 'grand' minima employed in some previous modeling studies. Despite the small reduction in total solar irradiance (0.36 W m−2), relatively large responses emerge in the winter Northern Hemisphere, with a reduction in regional-scale projected warming by up to 40%. To identify the origin of the enhanced regional signals, we assess the role of the different mechanisms by performing additional experiments forced only by irradiance changes at different wavelengths of the solar spectrum. We find that a reduction in visible irradiance drives changes in the stationary wave pattern of the North Pacific and sea–ice cover. A decrease in UV irradiance leads to smaller surface signals, although its regional effects are not negligible. These results point to a distinct but additive role of UV and visible irradiance in the Earth's climate, and stress the need to account for solar forcing as a source of uncertainty in regional scale projections.
     
  8. bd7

    bd7 Hard Yards

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    That should be enough to get things moving...
    LETTER • THE FOLLOWING ARTICLE IS OPEN ACCESS
    A simulated lagged response of the North Atlantic Oscillation to the solar cycle over the period 1960–2009
    M B Andrews1, J R Knight1 and L J Gray2

    Published 22 May 2015 • © 2015 IOP Publishing Ltd
    Environmental Research Letters, Volume 10, Number 5
    Abstract

    Numerous studies have suggested an impact of the 11 year solar cycle on the winter North Atlantic Oscillation (NAO), with an increased tendency for positive (negative) NAO signals to occur at maxima (minima) of the solar cycle. Climate models have successfully reproduced this solar cycle modulation of the NAO, although the magnitude of the effect is often considerably weaker than implied by observations. A leading candidate for the mechanism of solar influence is via the impact of ultraviolet radiation variability on heating rates in the tropical upper stratosphere, and consequently on the meridional temperature gradient and zonal winds. Model simulations show a zonal mean wind anomaly that migrates polewards and downwards through wave–mean flow interaction. On reaching the troposphere this produces a response similar to the winter NAO. Recent analyses of observations have shown that solar cycle–NAO link becomes clearer approximately three years after solar maximum and minimum. Previous modelling studies have been unable to reproduce a lagged response of the observed magnitude. In this study, the impact of solar cycle on the NAO is investigated using an atmosphere–ocean coupled climate model. Simulations that include climate forcings are performed over the period 1960–2009 for two solar forcing scenarios: constant solar irradiance, and time-varying solar irradiance. We show that the model produces significant NAO responses peaking several years after extrema of the solar cycle, persisting even when the solar forcing becomes neutral. This confirms suggestions of a further component to the solar influence on the NAO beyond direct atmospheric heating and its dynamical response. Analysis of simulated upper ocean temperature anomalies confirms that the North Atlantic Ocean provides the memory of the solar forcing required to produce the lagged NAO response. These results have implications for improving skill in decadal predictions of the European and North American winter climate.
     
  9. bd7

    bd7 Hard Yards

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    Interesting read guys
    https://theconversation.com/solar-weather-has-real-material-effects-on-earth-118453

    On Sep. 1, 1859, solar astronomer Richard Carrington witnessed sunspots that suddenly and briefly flashed brightly before they disappeared. Just before dawn the next day, auroras erupted over most of the Earth, reaching as far south as the Caribbean and Hawaii while southern lights were seen as far north as Chile. The event produced not only a visible light show in areas where they do not typically appear, but it also sent telegraph systems around the world haywire.

    Given the state of technology during Carrington’s time, the impact of a geomagnetic storm was limited to disruptions of telegraph service. If something similar happened today, the world’s technological infrastructure could grind to a halt. Extreme space weather events such as geomagnetic storms are more disruptive now than in the past. This is because of our greater dependence on technical systems that can be affected by electric currents and energetic particles high in the Earth’s atmosphere.