共查询到20条相似文献，搜索用时 203 毫秒
1.
This paper presents an empirical model for space-time distribution of the basic parameters of the general circulation of the atmosphere at ionospheric levels (E-and F-regions). The model is based on the results of a physico-statistical analysis of experimental data on the measurement of horizontal ionospheric drifts by close spaced receivers, carried out by the world network of stations in 1958–1970. This model allows an evaluation of the motion parameters at a given latitude, local time, season and the level of solar activity to be made. The limitations and shortcomings of the model are discussed, the results are compared with theoretical and semi-empirical schemes of the atmospheric general circulation, as well as with data of both rocket measurements of wind and drift measurements of plasma by the method of incoherent scatter of radio waves. The physics of the results obtained are stressed. The characteristics of the model are tested and defined using the materials af the coordinated program of drift measurements in the E-region from 8 stations of the northern hemisphere in 1971–1974. The characteristics of motions at higher latitudes and the longitudinal effect are discussed. 相似文献
2.
We suggest geoeffective independent parameters that can be calculated on the basis of conventional measurements of the solar wind, which allows them to be used to forecast space weather. We present the results of our analysis of the ground variations in planetary geomagnetic activity (K p ) and geoeffective parameters calculated on the basis of solar wind and interplanetary magnetic field measurements in the Earth’s orbit for the period 1964–1996 by taking into account the change in the orientation of the geomagnetic moment during the Earth’s diurnal and annual motions. 相似文献
3.
Photoelectric measurements of monochromatic spot intensities obtained with the domeless Coudé refractor in Anacapri are given. The scattered light superimposed on the spot, as deduced from measurements outside the sun's limb, amounts on the average to about 4% of the photospheric intensity. The accuracy of the derived spot intensities is better than 10%. Two of four investigated spots yielded temperatures below 3900K (ΔΘ > 0.5). 相似文献
4.
A new method of determination of the scattered light intensity, , by a unit-volume of interplanetary space is presented. From ground base Zodiacal Light measurements and the experimental results of Pioneer X the density, ρ(r), and phase functions, σ(ε), are obtained without any previous assumptions about them. 相似文献
5.
S. Kholikov 《Solar physics》2013,287(1-2):229-237
Using SOHO/MDI and GONG observations we present time–distance deep-focusing measurements to examine the deeper layers of the solar convective zone. The constructed travel-time maps show 10?–?15 second perturbations at depths of 40?–?75 Mm around active region locations before their emergence to the solar surface. The majority of the active regions used in this study were the same as those used in the recent work published by Ilonidis, Zhao, and Kosovichev (Science 333, 993, 2011). In order to confirm the capability of time–distance measurements to detect emerging active regions, we used a technique similar to their time–distance scheme. Our measurements only in some cases show a similar travel-time anomaly. Additionally, we have shown that the technique utilized in our study can provide more spatial details of the emerging flux configurations. 相似文献
6.
We present measurements of the longitudinal magnetic field component B ‖ of the young star BP Tau in the He I 5876 emission line formation region, i.e., in the accretion flow near the stellar surface. The values obtained (?1.7 kG and ?1.0 kG in 2000 and 2001, respectively) agree with the results of similar measurements by other authors. At the same time, we show that the previously obtained field strength at the magnetic pole, B p, and the inclination of the magnetic axis to the rotation axis, β, are untrustworthy. In our opinion, based on the B ‖ measurements available to date, it is not possible to conclude whether the star’s magnetic field is a dipole one or has a more complex configuration and to solve the question of whether this field is stationary. However, we argue that at least in the He I 5876 line formation region, the star’s magnetic field is not stationary and can be restructured in a time of the order of several hours. Nonstationary small-scale magnetic fields of active regions on the stellar surface and/or magnetospheric field line reconnection due to the twisting of these field lines as the star rotates could be responsible for the short-term magnetic field variability. It seems highly likely that there are no strictly periodic variations in brightness and emission line profiles in BP Tau due to the irregular restructuring of the star’s magnetic field. 相似文献
7.
Rocket borne Langmuir probe measurements of electron temperature in the E-region are examined in relation to recent laboratory investigations of surface drift effects which can lead to erroneously high and time-dependent electron temperature measurements. The rocket data is consistent with the laboratory expectations thus supporting the suggested importance of surface effects in rocket measurements and in relation to the E-region discrepancy with simultaneous incoherent radar scatter measurements. 相似文献
8.
New measurements are reported of the absorption cross sections of formaldehyde at 296 K and 223 K. These measurements are significantly lower than those reported in the earlier literature at ca. 353 K. The implications of the lower absorption cross sections for stratospheric chlorine chemistry are considered using a one dimensional atmospheric model. A slight modification to ClX partitioning is predicted for the new cross sections, with only a small effect on estimated chlorine-catalyzed ozone perturbations. 相似文献
9.
P. Persi 《Solar physics》1975,43(1):39-47
A new numerical method for the analysis of the high dispersion photospheric spectrum is described. In particular the method is applied to study the C2(0, 0) d 3 Πg-a a Πu molecular band. From measurements of the equivalent widths of C2 lines, a rotational temperature of 4450 ± 305 K is obtained, and the band intensity log W 0 /S 0 = ?0.051 ± 0.101 is found. 相似文献
10.
V. S. Vorobyev R. A. Burenin I. F. Bikmaev I. M. Khamitov S. N. Dodonov R. Ya. Zhuchkov E. N. Irtuganov A. V. Mescheryakov S. S. Melnikov A. N. Semena A. Yu. Tkachenko N. Aghanim R. A. Sunyaev 《Astronomy Letters》2016,42(2):63-68
We present the results of spectroscopic redshift measurements for the galaxy clusters from the first all-sky Planck catalogue that have been mostly identified based on the optical observations performed previously by our team (Planck Collaboration 2015a). Data on 13 galaxy clusters at redshifts from z ≈ 0.2 to z ≈ 0.8, including the improved identification and redshift measurement for the cluster PSZ1 G141.73+14.22 at z = 0.828, are provided. We have performed the measurements based on data from the Russian–Turkish 1.5-m telescope (RTT-150), the 2.2-m Calar Alto Observatory telescope, and the 6-m SAO RAS telescope (Bolshoy Teleskop Azimutalnyi, BTA). 相似文献
11.
Accurate absolute optical magnitude values (HV and HR) for Kuiper belt objects (KBOs) and Centaurs are becoming increasingly important as observations in other wavelengths, particularly SIRTF thermal infrared measurements, become available for large samples of objects. We present accurate HV and HR values for 90 KBOs and Centaurs, based on our published optical photometry. We find that our HV values are in good agreement with those available from the European photometric survey of minor bodies in the outer Solar System. Comparison with HV values from the JPL Horizons database and the Minor Planet Center database shows that these sources are systematically brighter than ours by about 0.3 mag. 相似文献
12.
Philippe L. Lamy 《Icarus》1978,34(1):68-75
Near-normal incidence reflectance measurements in the interval 1026–1640 Å were performed on four silicates already studied in the visible and infrared by Pollack et al. (1973). We use a Kramers-Kronig analysis of these data to calculate the complex index of refraction m = n ? ik. New transmission measurements improve the determination of k in the interval 2500–4500 Å, except for andesite, which is more opaque than found by Pollack et al. 相似文献
13.
Mark S. Bentley Andrew J. Ball Ian P. Wright John C. Zarnecki 《Planetary and Space Science》2011,59(1):79-91
Space weathering is now commonly accepted to modify the optical and magnetic properties of airless body regoliths throughout the Solar System. Although the precise formation processes are not well understood, the presence of ubiquitous sub-microscopic metallic iron (SMFe) grains in lunar soils and corresponding spectral analyses have explained both the unique optical and magnetic properties of such soils. More recently, a variety of ion irradiation, laser melting and vaporisation and impact experiments have been shown to reproduce these effects in the laboratory. Such experiments are crucial to the study of the formation of SMFe under controlled conditions. To date, more emphasis has been placed on optical analyses of laboratory samples, as these address directly the mineralogical interpretation of remote sensing data. However, the magnetic analyses performed on the Apollo and Luna samples have provided useful qualitative and quantitative evaluation of regolith metallic iron content. These techniques are reviewed here, demonstrated on pulsed laser irradiated olivine powder, and their utility for determining the quantity and size distribution of this metallic iron discussed. Ferromagnetic resonance, multi-frequency magnetic susceptibility, vibrating sample magnetometry and thermomagnetic measurements were carried out. Each showed trends expected for the conversion of paramagnetic Fe2+ in olivine to fine-grained Fe0, with some grains in the superparamagnetic size range. Although evidence for superparamagnetic iron was found, the quantity of sub-microscopic metallic iron produced in these experiments proved insufficient to make conclusive measurements of either the quantity or size distribution of this iron. Improvements to both the experimental and analytical procedures are discussed to better enable such measurements in the future. 相似文献
14.
Infrared polarimetry of Venus over the phase angles from 18 to 171° has been made extending previous measurements (S. Sato, K. Kawara, Y. Kobayashi, H. Okuda, K. Noguchi, T. Mukai, and S. Mukai (1980). Icarus43, 288) in both wavelength λ and phase angle θ. The results of polarization measurements at 2.25 μm ? λ ? 5.0 μm are (i) small positive and negative values at K(2.25 μm), (ii) a remarkable variation with λ in the CVF(2.2?4.2μm) filter region, (iii) a nearly smooth curve as a function of θ having a peak value of ～36% at θ ～ 90° at both 3.6 μm and L′(3.8 μm), and (iv) a decrease with increasing field of view at M(5.0 μm) due to the contamination of thermal emission from the dark crescent. Furthermore, at 3.6 μm and L′(3.8 μm), (v) higher values at the poles than at the equator and (vi) 4.5- to 5.9-day periodic fluctuations are also found. From a comparison with model calculations, the results confirm the existence of a thin haze layer consisting of submicron-size particles above the main clouds of Venus; e.g., its optical thickness is about 0.1 at λ ～ 0.94 μm. In addition, result (vi) could be explained by a variation of the optical thickness of the haze layer or that of the brightness temperature of the main clouds. 相似文献
15.
Proton measurements by two large area GM-counters (threshold energies Ep > 12 MeV and Ep > 30 MeV) on board the polar satellite GRSA/AZUR during the solar particle events of March 5–13,1970 are compared with similar measurements aboard Pioneer 8, HEOS Al, Explorer 41 and ATS 1. 相似文献
16.
W. Mattig 《Solar physics》1983,87(1):187-193
From aureole measurements made with a 40 cm-Vacuum-Telescope at Izaña (Tenerife) in the wavelength region 417 nm < λ < 785 nm and from a comparison with other aureole measurements we conclude the following: (a) Within one solar radius from the limb, the aureole is mostly of instrumental origin, (b) Beyond that distance, the contribution of atmospheric stray-light becomes noticeable, (c) The atmospheric contribution to the aureole intensity is, under good conditions at mountain stations, a very slowly decreasing function, and amounts to some 10?5 of the solar disk intensity. A procedure is given to separate the variable atmospheric component of the stray-light from the constant instrumental one. 相似文献
17.
V. G. Klochkova V. E. Panchuk M. V. Yushkin D. S. Nasonov 《Astrophysical Bulletin》2008,63(4):386-394
Solutions are considered that allow the accuracy of stellar radial velocity measurements with the spectroscopic instruments of the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences to be improved. The factors that limit the accuracy of spectroscopic V r measurements are analyzed both in general and for the particular design of the telescope and its housing. 相似文献
18.
19.
A.L. Doobov 《Planetary and Space Science》1973,21(3):532-534
Using measurements made at 3 sites, correlation coefficients are calculated between both the period and the frequency of a Pi2, on the one hand, and the planetary magnetic activity index and the magnitude of the accompanying auroral bay, on the other. The coefficients are consistently larger for frequency than for period. 相似文献
20.
A sounding rocket was launched in March 1982 from Thumba, India, shortly after sunrise. The measurements included the concentration of nitric oxide and ozone, the total ion density and the Lyman-α flux. Hence most parameters important for the formation of the D-region during daytime are available with the exception of solar radiation other than Lyman-α which only becomes important above 95 km. The mutual agreement is satisfactory which adds weight to the measurements. 相似文献