The data obtained by the BAT γ-ray telescope on board the SWIFT satellite in the energy range of 15-350 keV with a time resolution of 64 ms were used to study the temporal structure of the γ-ray burst GRB 190114C emission by means a modified spectral analysis technique. The analysis revealed quasi-periodic fluctuations with main periods of 3.84 s and 2.24 s. Both oscillations start simultaneously, continue throughout of the burst, and are equally modulated. Based on this evidence, it can be argued that all three episodes of the burst were controlled by one “central engine”.
The effect powerful solar proton events have on changes in temperature in layers of the Earth’s atmosphere up to 41 km above the surface at the decrease stage of 23rd cycle of solar activity is investigated. It is found that during proton events, the temperature of the bottom layers of the Earth’s atmosphere (at altitudes up to 11 km) rises on average by 0.08 K, and for the upper layers (from 17 to 41 km) it falls on average by 0.18 K. For 3–8 days after the event, the observed effect is reversed. The changes in temperature at sea level and in the atmospheric layer at 14 km (the most likely position of the tropopause) do not display such a tendency.
The γ-ray burst GRB 080319B light curve, observed in the energy range from 15 to 350 keV with a 64-ms time resolution by the Swift/BAT mission, has been investigated using a modified method of spectral analysis. The light curve revealed quasi-periodic oscillations with periods from 0.7 to 6 s, in particular, oscillations with constant periods of 0.89 and 1.28 s, independent of the γ-ray energy.
modified spectral analysis technique is used to study the temporal structure of the emission from the γ -ray burst GRB 080319B detected in three space missions, Swift/BAT, Wind/KONUS, and Integral/SPI ACS. The energy range of the γ rays detected in these experiments covers 15-10000 keV. The time resolution for the first two of these experiments was 64 ms and for the third, 50 ms. Quasiperiodic oscillations with periods from 0.6 s to 6 s were observed. To within the time resolution, the oscillations with periods of 1.28, 0.89, and 0.64 s are the second, third, and fourth harmonics, respectively, of oscillations with a period of 2.56 s, while oscillations with a period of 0.96 s are the third harmonic of oscillations with a period of 2.94 s. The behavior of the quasiperiodic components is examined as a function of the phase of the events. Possible physical mechanisms for the quasiperiodic oscillations in the light curves of γ -ray bursts are discussed.
The time structure and energy spectrum evolution of the X-ray emission of solar flares, observed by the IRIS spectrometer onboard the CORONAS-F spacecraft, are investigated. It has been found out that one or two quasi-periodic components with periods of 1–20 s, which are absent in the background preflare emission, appear in the flare soft X rays. It has been indicated that the variation in the shape of the energetic spectra of the C-class flare hard X rays reflects the evolution of the accelerated electron distribution function.
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.
A method for collating time series of partially or fully simultaneous measurement into a unified weighted-averaged series particular on an interval enveloping all initial measurements was designed. This method is applied to GOES data obtained during the 22nd and 23rd solar-activity cycles to synthesize the daily-average series of the soft X-ray emission from the Sun at wavelengths 1–8 Å, the electron, proton, and α-particle fluxes in the energy ranges >2 MeV, >5MeV, and 4–10 MeV, respectively, and the magnitude of the total geomagnetic-field vector. The time structure of the above data series was studied by means of the spectral analysis. Correlations of the “flare” and “background” solar soft X-ray emissions with the above-mentioned particle fluxes and the geomagnetic field are studied.
Long-term changes of the Arctic frontal zone characteristics near the south-eastern coasts of Greenland were considered, the NCEP/NCAR reanalysis data being used. It was found that in the cold half of the year the temperature gradients in the layer 1000–500 hPa in the region under study reveal strong ∼10-yr and ∼22-yr periodicities that seem to be related to solar activity cycles. The results obtained suggest the influence of solar activity and cosmic ray variations on the structure of the temperature field of the troposphere resulting in the changes of the temperature contrasts in the Arctic frontal zone that, in turn, may affect the intensity of cyclogenesis at middle latitudes. The detected effects seem to indicate an important part of frontal zones in the mechanism of solar activity and cosmic ray variation influence on the development of extratropical baric systems. It is suggested that the variations of the temperature gradients revealed in the Arctic frontal zone are due to the radiative forcing of cloudiness changes which may be associated with geomagnetic activity and cosmic ray variations.
Long-term changes of the characteristics of frontal zones, which are the regions of high temperature contrasts influencing extratropical cyclone formation and development, were studied in the North Atlantic, the 'reanalysis' data NCEP/NCAR being used. It was found that in the cold half of the year (the period of most intensive cyclogenesis at middle latitudes) the oscillations of the temperature gradients in the layer 1000-500 hPa near the south-eastern coasts of Greenland (the Arctic frontal zone) reveal strong ∼10-yr and ∼22-yr periodicities. The detected effects provide evidence of the influence of solar activity and related phenomena on the structure of the thermo-baric field of the troposphere at middle and high latitudes resulting in the enhancement of temperature contrasts in the frontal zones. In turn, the revealed changes of the frontal zone characteristics may be a reason for long-period changes of cyclonic activity at middle latitudes.
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.
Long-term variations of the surface pressure in the North Atlantic for the period 1874–1995 (Mean Sea Level Pressure archive, Climatic Research Unit, UK) were compared with indices of solar and geomagnetic activity and the galactic cosmic ray (GCR) variations characterized by the concentration of the cosmogenic isotope 10Be. A periodicity of ∼80 yrs close to the Gleissberg cycle in the intensity of the 11-yr solar cycles was found in the pressure variations at middle latitudes (45–65°N) in the cold half of the year, which is the period of intensive cyclogenesis. It was shown that a long-term increase of pressure in this region coincided with a secular rise of solar/geomagnetic activity which was accompanied by a decrease in GCR intensity. Long-term decreases of pressure were observed during the periods of low (or decreasing) intensities of sunspot cycles. Similar features were also found in the spectral characteristics of geomagnetic activity indices, GCR intensity and pressure at middle latitudes on the quasi-decadal time scale. Effects of solar activity/GCR variations on the surface pressure seem to be more pronounced in the North Atlantic zone of intensive cyclogenesis (near the eastern coasts of North America). The results obtained suggest possible links between long-term variations in cyclonic activity at extratropical latitudes of the North Atlantic and solar activity/GCR variations on the time scales from ∼10 to ∼100 yrs.
The oscillations in solar daily soft X-rays (SXR) have been analyzed for 22 cycle ones within data uncertainty (1 day) and their values may be explained by the differential rotation of the solar chromosphere and corona.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html
Sub-second time structure of hard X-rays observed during solar flares by spectrometer “IRIS” on a board of CORONAS satellite are discussed. The burst duration of 80ms and FWHM about 30ms are recorded in powerful flare of August 20, 2002 year at 0828:16.77 UT. A confidence level of this peak is 6$\sigma$.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html