P. Dalin
Swedish Institute of Space Physics
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Featured researches published by P. Dalin.
Advances in Space Research | 2000
G. N. Zastenker; P. Dalin; K. I. Paularena; J. D. Richardson; F. Dashevskiy
Abstract Solar wind plasma correlations are investigated using data from three widely-separated spacecraft (IMP 8, WIND, INTERBALL-1) for the years 1994–1997. The tasks of this study have been directed toward a statistical understanding of solar wind correlation behaviour. Using the large statistics for 6-hour periods (more then 2500 segments) we obtained the average plasma correlation about 0.7. The correlations were examined as a function of the solar wind ion flux, the standard deviation of the flux, and positional separations between spacecraft. It was shown that the variability of ion flux (or density) is the strongest organizational factor among the other plasma parameters. Also our data revealed that positional dependence of the solar wind plasma correlations up to 200 Re along Xse or to 100 Re along Yse or Zse is rather weak or absent.
Journal of Atmospheric and Solar-Terrestrial Physics | 2002
M.O. Riazantseva; P. Dalin; A.V. Dmitriev; Yu. V. Orlov; K. I. Paularena; J. D. Richardson; G. N. Zastenker
Solar wind plasma and magnetic field observations from multiple spacecraft can be used to separate temporal and spatial variations and to determine the accuracy of predictions of solar wind conditions near Earth based on distant-spacecraft measurements. The study of correlations between the ion fluxes measured by three spatially separated spacecraft (IMP 8, WIND and INTERBALL-1) was one of the first steps in this direction. This paper describes a complex multifactor analysis of different physical, geometrical, and statistical parameters that control such correlations (considered separately and in combination). A linear-regression and an artificial neural network techniques are used for this analysis. The analysis is applied to an extensive array of correlation coefficients for the ion flux in the solar wind and provides estimates of the relative significance of the factors that control these correlation coefficients. The study shows that the most influential parameters are the solar wind density and the standard deviations of solar wind density, solar wind velocity and interplanetary magnetic field. This set of parameters permits us to develop a sufficiently accurate (with a relative error of less than a few per cent) quantitative model for the correlation between the ion fluxes measured on two spatially separated spacecraft.
Journal of Geophysical Research | 2016
Ingrid Mann; Ingemar Häggström; Anders Tjulin; S. Rostami; Cc Anyairo; P. Dalin
(c) American Geophysical Union, reprinted with permission. Article also available at source: https://doi.org/10.1002/2016JA023080
Journal of Atmospheric and Solar-Terrestrial Physics | 2002
P. Dalin; G. N. Zastenker; K. I. Paularena; J. D. Richardson
Abstract In this work solar wind measurements from several spacecraft were used to investigate the correlations of solar wind plasma parameters. These results provide a test of the concept of predicting space weather by monitoring the condition of the solar wind at a large distance (up to 230Re, the L1 point) upstream from the Earth. We compared the ion flux and bulk velocity time behavior measured by widely-separated spacecraft: the spacecraft pairs INTERBALL-1 and IMP 8 (separations up to 30Re), INTERBALL-1 and WIND, and IMP 8 and WIND (both with separations up to 250Re). The average value of the ion flux correlation coefficient is about 0.73. But in some cases the plasma parameters from two spacecraft are very different in both behavior and value, so correlations are very poor. The technique of multifactorial analysis was used to obtain the physical dependences of the correlations on the spacecraft separation and on different plasma and magnetic field parameters. We found that the correlation values have a weak but significant dependence on the separation perpendicular to the Sun–Earth line (YZse-separations up to 90Re). The most important factors influencing the correlation level are density (or ion flux) variability, the direction of the IMF vector to the Sun–Earth line (cone angle), and the solar wind bulk velocity.
The solar wind nine conference | 2008
K. I. Paularena; J. D. Richardson; G. N. Zastenker; P. Dalin
Recent work on solar wind plasma correlations using data from several widely-separated spacecraft (IMP 8, INTERBALL-1, WIND, and ISEE-3) has shown that, for 6-hour periods, the average plasma correlation is ∼0.7. The focus of these studies has been directed toward a statistical understanding of gross solar wind correlation behavior. In all correlations examined, lower average correlations are caused by the presence of many points from the low correlation subpopulation; nevertheless, data points from the high correlation population are still present. No single organizational factor has yet been found which adequately separates low-correlation periods from high-correlation periods. Some of the spread in correlations is due to the spatial orientations and dimensions of solar wind structures, and thus to the locational alignments of the spacecraft being correlated, but this does not adequately explain all the good or poor correlations since sometimes three nearby spacecraft show poor correlations, while somet...
Geophysical Research Letters | 2015
P. Dalin; A. Pogoreltsev; N. A. Pertsev; V. I. Perminov; N. Shevchuk; A. Dubietis; M. Zalcik; S. Kulikov; A. Zadorozhny; D. Kudabayeva; A. Solodovnik; G. Salakhutdinov; I. Grigoryeva
We consider a unique case of a propagating internal gravity wave that has generated in situ a compact and thin layer of noctilucent clouds (NLC) at 82.7–85.2 km with a characteristic horizontal scale of 65–70 km, as observed in the Moscow region on the night of 18–19 July 2013. This particular transient isolated gravity wave together with the whole NLC layer suddenly appeared in the clear twilight sky and lasted about 1 h traveling eastward, which differs significantly from previously observed cases of gravity waves propagating through preexisting NLC layers. Our model studies demonstrate that the wave had a tropospheric source connected to the passage of an occluded front. The wave was likely generated due to strong horizontal wind shears at about 5 km altitude.
Journal of Geophysical Research | 2016
P. Dalin; Nikolai M. Gavrilov; N. A. Pertsev; V. I. Perminov; A. Pogoreltsev; N. Shevchuk; A. Dubietis; P. Völger; M. Zalcik; A. Ling; S. Kulikov; A. Zadorozhny; G. Salakhutdinov; I. Grigoryeva
Atmospheric gravity waves with very long crests (of 450-500 km length) and short horizontal wavelengths of about 20 km were observed in noctilucent clouds and were studied in detail for the first time. The gravity waves were slowly moving in opposite direction to the background wind indicating their forced generation outside the mesopause region. A ray-tracing analysis using meteorological reanalysis and empirical atmospheric model data shows that a source of such peculiar gravity waves observed in noctilucent clouds was located near the tropopause and could be associated with the jet stream at altitudes 8-10 km. Two considered examples of very long wave crests confirm a significant role of the upper tropospheric jet stream as a source of gravity waves and reveal that these waves could propagate without critical levels to the mesopause in summertime.
Archive | 1999
K. I. Paularena; J. D. Richardson; G. N. Zastenker; P. Dalin
Solar wind plasma correlations between data from three spacecraft — IMP 8, INTERBALL-1, and WIND — are analyzed for periods near the most recent solar minimum. There are two primary foci of this study: 1) to understand the physics underlying good and poor correlation periods, and 2) to investigate and quantify the degree to which distant solar wind plasma measurements (such as those from near Earth’s L1 point) represent the solar wind affecting the magnetosheath and magnetosphere.
Annales Geophysicae | 2008
S. Kirkwood; P. Dalin; A. Réchou
Annales Geophysicae | 2006
S. Kirkwood; Phillip B. Chilson; E. Belova; P. Dalin; Ingemar Häggström; M. T. Rietveld; Werner Singer