Viewpoints concerning solar activity effects on the atmospheric circulation and climate

Author(s):  
C. J. E. Schuurmans
2021 ◽  
Author(s):  
Sergey Molodykh ◽  
Ashkhen A. Karakhanyan ◽  
Kirill K. Kirichenko

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1526
Author(s):  
Chen-Ke-Min Teng ◽  
Sheng-Yang Gu ◽  
Yusong Qin ◽  
Xiankang Dou

In this study, a global atmospheric model, Specified Dynamics Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (SD-WACCM-X), and the residual circulation principle were used to study the global atmospheric circulation from the lower to upper atmosphere (~500 km) from 2002 to 2019. Our analysis shows that the atmospheric circulation is clearly influenced by solar activity, especially in the upper atmosphere, which is mainly characterized by an enhanced atmospheric circulation in years with high solar activity. The atmospheric circulation in the upper atmosphere also exhibits an ~11 year period, and its variation is highly correlated with the temporal variation in the F10.7 solar index during the same time series, with a maximum correlation coefficient of up to more than 0.9. In the middle and lower atmosphere, the impact of solar activity on the atmospheric circulation is not as obvious as in the upper atmosphere due to some atmospheric activities such as the Quasi-Biennial Oscillation (QBO), El Niño–Southern Oscillation (ENSO), sudden stratospheric warming (SSW), volcanic forcing, and so on. By comparing the atmospheric circulation in different latitudinal regions between years with high and low solar activity, we found the atmospheric circulation in mid- and high-latitude regions is more affected by solar activity than in low-latitude and equatorial regions. In addition, clear seasonal variation in atmospheric circulation was detected in the global atmosphere, excluding the regions near 10−4 hPa and the lower atmosphere, which is mainly characterized by a flow from the summer hemisphere to the winter hemisphere. In the middle and low atmosphere, the atmospheric circulation shows a quasi-biennial oscillatory variation in the low-latitude and equatorial regions. This work provides a referable study of global atmospheric circulation and demonstrates the impacts of solar activity on global atmospheric circulation.


2016 ◽  
Vol 12 (3) ◽  
pp. 799-805 ◽  
Author(s):  
Markus Czymzik ◽  
Raimund Muscheler ◽  
Achim Brauer

Abstract. Solar influences on climate variability are one of the most controversially discussed topics in climate research. We analyze solar forcing of flood frequency in central Europe during spring and summer on interannual to multi-centennial timescales, integrating daily discharge data of the River Ammer (southern Germany) back to AD 1926 (∼  solar cycles 16–23) and the 5500-year flood layer record from varved sediments of the downstream Ammersee. Flood frequency in the River Ammer discharge record is significantly correlated to changes in solar activity when the flood record lags the solar signal by 2–3 years (2-year lag: r = −0.375, p = 0.01; 3-year lag: r = −0.371, p = 0.03). Flood layer frequency in the Ammersee sediment record depicts distinct multi-decadal variations and significant correlations to a total solar irradiance reconstruction (r = −0.4, p <  0.0001) and 14C production rates (r = 0.37, p <  0.0001), reflecting changes in solar activity. On all timescales, flood frequency is higher when solar activity is reduced. In addition, the configuration of atmospheric circulation associated with periods of increased River Ammer flood frequency broadly resembles that during intervals of reduced solar activity, as expected to be induced by the so-called solar top-down mechanism by model studies. Both atmospheric patterns are characterized by an increase in meridional airflow associated with enhanced atmospheric blocking over central Europe. Therefore, the significant correlations as well as similar atmospheric circulation patterns might provide empirical support for a solar influence on hydroclimate extremes in central Europe during spring and summer by the so-called solar top-down mechanism.


2020 ◽  
Author(s):  
Andrey Koval ◽  
Nikolai Gavrilov ◽  
Alexander Pogoreltsev ◽  
Nikita Shevchuk

&lt;p&gt;Atmospheric large-scale disturbances, for instance planetary waves, play a significant role in atmospheric general circulation, influencing its dynamical and thermal conditions. Solar activity may influence the mean temperature at altitudes above 100 km and alter conditions of wave propagation and reflection in the thermosphere. Using numerical simulations of the general atmospheric circulation during boreal winter, statistically confident evidences are obtained for the first time, demonstrating that changes in the solar activity (SA) in the thermosphere at heights above 100 km can influence propagation and reflection conditions for stationary planetary waves (SPWs) and can modify the middle atmosphere circulation below 100 km. A numerical mechanistic model simulating&amp;#160; atmospheric circulation and SPWs at heights 0 &amp;#8211; 300 km is used. To achieve sufficient statistical confidence, 80 pairs of 15-day intervals were extracted from an ensemble of 16 pairs of model runs corresponding to low and high SA. Results averaged over these intervals show that impacts of SA above 100 km change the mean zonal wind and temperature up to 10% at altitudes below 100 km. The statistically confident changes in SPW amplitudes due to SA impacts above 100 km reach up to 50% in the thermosphere and 10 &amp;#8211; 15% in the middle atmosphere depending on zonal wavenumber. Changes in wave amplitudes correspond to variations of the EP-flux and may alter dynamical and thermal SPW impacts on the mean wind and temperature. Thus, variable conditions of SPW propagation and reflection at thermospheric altitudes may influence the middle atmosphere circulation, thermal structure and planetary waves at different altitudes.&lt;/p&gt;


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