S. V. Veretenenko

Solar activity and cosmic ray variations as a factor of intensity of cyclonic processes at midlatitudes

Long-period variations in the cyclonic activity at middle and subpolar latitudes of the North Atlantic are studied on the basis of the data from the MSLP archive of the surface pressure (Climatic Research Unit, UK) for 1874–1995. It has been found that in the cold half year (the period of the most intense formation and development of extra-tropical cyclones) in the studied region, oscillations of the surface pressure with periods close to the main periods of solar activity (∼80 and ∼11 years) are observed. The obtained results make it possible to assume that solar activity and related variations in the galactic cosmic rays are one of the factors influencing the intensity of cyclonic processes at midlatitudes on the time scales of ∼10 to ∼100 years.

Solar proton events and evolution of cyclones in the North Atlantic

The influence of solar proton events (SPEs) with particle energies > 90 MeV on the evolution of extratropical cyclones in the North Atlantic is studied. A substantial intensification of the regeneration (secondary deepening) of cyclones near the southeastern Greenland coast after the SPE onset is detected. It is shown that the observed deepening of cyclones is caused by intensified advection of cold when the zone of the Arctic front in the region of the Greenland coast is approached. The results allow us to assume that SPEs with the above particle energies cause substantial changes in the structure of the thermobaric field of the subpolar and high-latitude troposphere, which form more favorable conditions for the regeneration of cyclones. In this case the role of the Arctic vertical frontal zone is apparently important. Temperature field changes can be caused by the radiation effects of variations in the upper cloudiness.

Study of spatial and temporal structure of long-term effects of solar activity and cosmic ray variations on the lower atmosphere circulation

The spatial and temporal structure of the effects of solar activity (SA) and galactic cosmic ray (GCR) flux variations on the lower atmosphere circulation has been studied based on NCEP/NCAR reanalysis archive for 1948–2006 and MSLP (Climatic Research Unit, UK) data for 1873–2000. It has been shown that the GCR effects on pressure variations are characterized by a strong latitudinal and regional dependence, which is determined by specific features of the tropospheric circulation in the studied regions. The distribution of the correlation coefficients for mean yearly values of atmospheric pressure with the GCR flux intensity is closely related to the position of the main climatological fronts. The periodic (∼60 years) changes in the correlation sign of the pressure at high and middle latitudes with Wolf numbers have been revealed. It has been suggested that the changes of the sign of SA/GCR effects on atmospheric pressure are caused by the changes of the macrocirculation epochs, which, in turn, may be related to large-scale processes on the Sun.

Solar activity and cosmic rays: Influence on cloudiness and processes in the lower atmosphere (in memory and on the 75th anniversary of M.I. Pudovkin)

The works by M.I. Pudovkin and his group devoted to studies of the influence of cosmic ray fluxes modulated by solar activity variability on the processes in the lower atmosphere and climatic parameters are briefly analyzed. The issues to be addressed for the solution of the problem are identified.

Effect of solar and galactic cosmic rays on the duration of macrosynoptic processes

The effect of solar and galactic cosmic ray variations on the duration of elementary synoptic processes (ESPs) in the Atlantic-European sector of the Northern Hemisphere has been studied. It has been found that solar cosmic ray (SCR) bursts result in an increase in the duration of ESPs, which belong to the western and meridional forms of atmospheric circulation. Forbush decreases in galactic cosmic rays (GCRs) are accompanied by an increase in the duration of ESPs, which belong to the meridional atmospheric circulation form, and in a decrease in the duration of ESPs, which are related to the western and eastern circulation forms. It has been assumed that the observed variations in the ESP duration are caused by the effect of short-period cosmic ray variations on the intensity of cyclonic processes at middle and high latitudes, namely, the regeneration of cyclones near the southeastern coast of Greenland after SCR bursts and the development of blocking anticyclones over the northeastern Atlantic, Europe, and Scandinavia during GCR Forbush decreases.

Stratospheric circumpolar vortex as a link between solar activity and circulation of the lower atmosphere

Possible reasons for the temporal variability of solar activity (SA) and galactic cosmic ray (GCR) effects on the tropospheric circulation are studied. Long-term variations in the amplitude and sign of SA/GCR effects are shown to be closely related to the state of the stratospheric circumpolar vortex. A ∼60-year periodicity was detected the vortex strength which affects the evolution of the large-scale atmospheric circulation. It is shown that the correlation coefficients between pressure in the troposphere and SA/GCR characteristics change the sign in the periods of transformations of the large-scale circulation caused by changes in the state of the vortex. The obtained results suggest an important part of the circumpolar vortex in the mechanism of solar-climate links.

Possible Contribution of Variations in the Galactic Cosmic Ray Flux to the Global Temperature Rise in Recent Decades

The field area of the Earth’s lower (<3.2 km) clouds is shown to correlate significantly with the intensity of galactic cosmic rays in 1983–2010, with the sign of correlation reversing in 2003. The same effect is discovered in the correlation between air temperatures in various regions of the Earth and the relativistic electron fluxes with energies of 30–300 KeV that precipitate in winter (December–February). An energy-balance climate model is used to estimate the possible contribution of lower clouds to the globally averaged temperature in the indicated period. It is shown that the consideration of lower clouds as a radiative forcing allows one to explain the global warming of the last 30 years without employing the hypothesis of anthropogenic greenhouse heating.

The circumpolar vortex as a cause for time variations in the effects of solar activity and galactic cosmic rays on the circulation of the lower atmosphere

We explore possible causes for time variations in the long-period effects of solar activity (SA) and variations in galactic cosmic rays (GCRs) on the circulation of the lower atmosphere. It is shown that the observed variations in the amplitude and sign of the SA/GCR effects are closely related to the evolution of the circumpolar vortex forming in the high-latitude stratosphere.

Long-period variations in the characteristics of frontal zones in the north Atlantic and their relation to solar activity and cosmic ray variations

The oscillations of the temperature gradients with the periods of ∼10 and ∼22 years have been detected in the Arctic frontal zone near the Greenland coasts. It has been shown that geomagnetic activity and the rate of variations in the GCR flux in the 11-year solar cycle are the main factors affecting the temperature contrasts in the frontal zone. It has been noted that the detected variations in the frontal zone temperature characteristics are important for the formation of the solar activity effects on the intensity of extratropical cyclogenesis.