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We have studied Ca II K line profiles, using two time series of spectrograms taken in two regions near the solar disk center. In each of the regions, the spectrograph slit cut out several areas of the quiet region and a plage. For the selected chromospheric structures, we have derived K line profiles and have defined a number of parameters that characterize the spatial and temporal variations of the profiles. The analysis of profile shapes in different structures belonging to the same moment of time has shown that there are structures whose profiles differ only slightly from each other in the photosphere, but differ dramatically in the chromosphere. The structures begin to differ from the level of formation of K 1 and continue to differ further in the chromosphere. There are, however, structures which begin to differ at the level of the photosphere and continue to differ in the chromosphere. The difference between profile shapes in different structures is likely to be associated both with different thermodynamic conditions and with different magnetic field topology at a given point at a given time. We have examined temporal variations of the Ca II K line profiles in structural chromospheric elements, which are caused by the process of K 2v grains. In most of the studied areas of the chromospheric structures, the brightening of the K 2v peak develops according to the "common" scenario: at the time of maximum brightness, the line shifts toward the red side. There are, however, cases when the brightening of the K 2v peak occurs with a shift of the line to the violet side or with no shift at all. We have constructed scatter plots for some pairs of profile parameters related to intensities at characteristic points of the profile and their shifts. A correlation has been found between intensities in the center and wings of the K line. The correlation between shifts of the K 2v and K 2r peaks is very weak or completely absent.

UDC 550.388.2 In the present work, results of vertical sensing of the ionosphere at the Klyuchi (Novosibirsk) and Arti (Ekaterinburg) Geophysical Observatories during the solar eclipse on March 29, 2006 are given. The maximum eclipse was observed in Novosibirsk at 11:43 UT; the obscuring phase was 92%. A maximum obscuring phase of 80% was observed at the Arti Georhysical Observatory at 11:32 UT. The results obtained are compared with the analogous data obtained in the preceding and next days as well as with the data of many-year observations on March 28, 29, and 30. The results obtained demonstrate that the eclipse affects most strongly the characteristics of the F layer. The maximum variations of the critical frequency f 0 F2 were delayed by about 10 min from the maximum eclipse phase, relaxation started half an hour after the maximum eclipse phase, and the frequency decreased at most by 1.5 MHz. A decrease in the critical frequency of the F1 layer has a greater delay and smaller amplitude. The results obtained are in good agreement with previous measurements.Experimental observations during solar eclipses which allow one to follow the response of the ionosphere to shortterm changes of ionizing solar radiation are difficult because they are rare in occurrence and places of their observation are widely spaced. The ionospheric response is characterized by an increase in radio-wave reflection altitudes and a decrease in the electron concentration in the Е and F layers, that is, a decrease in the total electron content in the ionosphere typical of the transition to the nighttime ionosphere [1][2][3][4][5]. The basic parameters of the ionospheric response are the delay of changes in these characteristics from different eclipse phases as well as their amplitude and duration. Results of numerous experimental observations demonstrate that the response delay changes approximately from 15 to 30 min, and its duration ranges from one hour to two-three hours, though in some cases it can reach several hours [5][6][7][8]. The influence of the eclipse on August 11, 1999 on changes in the f 0 F2 critical frequencies was reliably established in [9] based on the data obtained at 70 stations of the global GPS network. One of the reasons for a wide scatter in the parameters of the ionospheric response to the solar eclipse is the application of measurement methods that differ significantly by their spatial and temporal resolution. However, the main reason is a variety of the eclipse parameters (the phase and elevation above the horizon), geophysical conditions, and space and time parameters (coordinates of the observation stations and local times) during observations.In the present work, preliminary results of ionospheric measurements at the Klyuchi Geophysical Observatory in Novosibirsk and Arti Geophysical Observatory in Ekaterinburg during the solar eclipse on March 29, 2006 are given. Observations during eclipses have already been performed at these observatories. Thus, a series of observations, including vertical sensing of the ...

We have studied Ca II K line profiles, using two time series of spectrograms taken in two regions near the solar disk center. In each of the regions, the spectrograph slit cut out several areas of the quiet region and a plage. For the selected chromospheric structures, we have derived K line profiles and have defined a number of parameters that characterize the spatial and temporal variations of the profiles. The analysis of profile shapes in different structures belonging to the same moment of time has shown that there are structures whose profiles differ only slightly from each other in the photosphere, but differ dramatically in the chromosphere. The structures begin to differ from the level of formation of K1 and continue to differ further in the chromosphere. There are, however, structures which begin to differ at the level of the photosphere and continue to differ in the chromosphere. The difference between profile shapes in different structures is likely to be associated both with different thermodynamic conditions and with different magnetic field topology at a given point at a given time. We have examined temporal variations of the K Ca II line profiles in structural chromospheric elements, which are caused by the process of K2v-grains. In most of the studied areas of the chromospheric structures, the brightening of the K2v peak develops according to the “common” scenario: at the time of maximum bright-ness, the line shifts toward the red side. There are, however, cases when the brightening of the K2v peak occurs with a shift of the line to the violet side or with no shift at all. We have constructed scatter plots for some pairs of profile parameters related to intensities at characteristic points of the profile and their shifts. A correlation has been found between intensities in the center and wings of the K line. The correlation between shifts of the K2v and K2r peaks is very weak or completely absent.

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