Spectrophotometric experiment on the Verera-11 and Venera-12 descent vehicles: Some results of the analysis of the spectrum of the daytime sky of Venus

The spectra of the daytime sky of Venus were recorded on the Venera-11 and Venera-12 descent vehicles at various altitudes above the planet's surface, within the interval of 4500 to 12,000 Angstroms. The angular distribution of the brightness of the scattered radiation was recorded and the ratio of water and carbon dioxide were studied, with respect to the cloud cover boundaries

The Planetary Fourier Spectrometer (PFS) onboard the European Mars Express mission

International audience; The Planetary Fourier Spectrometer (PFS) for the Mars Express mission is an infrared spectrometer optimised for atmospheric studies. This instrument has a short wave (SW) channel that covers the spectral range from 1700 to 8200.0cm-1 (1.2- 5.5mum) and a long-wave (LW) channel that covers 250- 1700cm-1 (5.5- 45mum). Both channels have a uniform spectral resolution of 1.3cm-1. The instrument field of view FOV is about 1.6o (FWHM) for the Short Wavelength channel (SW) and 2.8o (FWHM) for the Long Wavelength channel (LW) which corresponds to a spatial resolution of 7 and 12 km when Mars is observed from an height of 250 km. PFS can provide unique data necessary to improve our knowledge not only of the atmosphere properties but also about mineralogical composition of the surface and the surface-atmosphere interaction. The SW channel uses a PbSe detector cooled to 200-220 K while the LW channel is based on a pyroelectric ( LiTaO3) detector working at room temperature. The intensity of the interferogram is measured every 150 nm of physical mirrors displacement, corresponding to 600 nm optical path difference, by using a laser diode monochromatic light interferogram (a sine wave), whose zero crossings control the double pendulum motion. PFS works primarily around the pericentre of the orbit, only occasionally observing Mars from large distances. Each measurements take 4 s, with a repetition time of 8.5 s. By working roughly 0.6 h around pericentre, a total of 330 measurements per orbit will be acquired 270 looking at Mars and 60 for calibrations. PFS is able to take measurements at all local times, facilitating the retrieval of surface temperatures and atmospheric vertical temperature profiles on both the day and the night side

VEGA 1 and VEGA 2 entry probes: An investigation of local UV absorption (220-400 nm) in the atmosphere of Venus (SO 2 aerosols, cloud structure)

International audienceIn 1985 the VEGA 1 and VEGA 2 spacecraft dropped two descent probes into the nightside of Venus. On board was the French-Russian ISAV ultraviolet spectroscopy experiment, consisting of a UV light source absorbed by atmospheric constituents circulating freely into a tube attached outside the pressurized modules. ISAV generated a wealth of absorption spectra in the 220- to 400-nm range with an unprecedented vertical resolution (60-170 m) from 62 km of altitude down to the ground. On the basis of known instrument properties and a careful examination of the light curves recorded in 13 wavelength intervals in the UV, we show that most of the recorded differential absorption (at each wavelength with respect to 394 nm) can be explained by a combination of gaseous SO2 absorption and absorption by aerosols deposited on the mirrors during the crossing of Venus' lower cloud. The spectral signature of this absorber, termed X, was obtained, thanks to an unexpected shock on VEGA 1 which removed this absorber from the mirrors at 18 km of altitude. The UV spectral signature of X resembles that of croconic acid, C5O5H2, whose absorbing power as a contaminant of H2SO4 droplets at 2.5% dilution is compatible with the observations. However, the nonidentity of the spectral signature, together with stability arguments, makes this identification less plausible. Whatever its nature, the relevance of this new absorber X is discussed in connection with the albedo of Venus and the IR variable leak windows. If this absorber X detected by ISAV in the lower cloud were also present in the upper cloud, it would be a good candidate to explain the UV part (λ<400 nm) of the Venus albedo. Three layers of absorbing material, called b, c, and d, are identified in the data of both ISAV 1 and 2 in the altitude range 49-43 km. The higher layer b is inside the lower cloud identified by the nephelometer of Pioneer Venus, while the two other layers are well below the lower cloud boundary as measured by Pioneer Venus. The SO2 profile (from 60 km down to 10 km) is characterized for ISAV 1 by a double peak of the mixing ratio (150 ppmv at 51.5 km, 125 ppmv at 42.5 km) separated by a deep trough at 30 ppmv at 45.6 km. For ISAV 2 there is a single peak at 43 km. Both SO2 profiles are quite compatible with recent ground-based measurements, showing 130+/-40 ppmv in the altitude range of 35-45 km [Bézard et al., 1993]. Below the clouds the measured SO2 mixing ratio decreases steadily on both probes, down to 25+/-2 ppmv at 10 km for ISAV 1, which is lower than previously reported values from gas chromatograph measurements (shown to be incompatible with ISAV measurements). The variation of SO2 mixing ratio with altitude implies a strong vertical transport which is given as a function of altitude, showing the source and sink regions of SO2 from 10 to 60 km of altitude. These data should impose severe constraints on future chemical models of the atmosphere of Venus, occurring after volcanic episodes or impact cratering events. The total SO2 column density (0-60 km) was measured to be 4×1022 molecules cm-2 or 4.2 gcm-2, a factor of 5 below previous estimates. With an average reaction rate of 4.6×1010 molecules cm-2s-1 with calcite, CaCO3, estimated by Fegley and Prinn [1989], it would take only 27,000 years to get rid of SO2 and associated H2SO4 droplets if calcite were present all over the surface of Venus. Therefore SO2 and its associated ubiquitous cloud cover may only be transient phenomena in the life of Venus

Temperature Dependence of the Resonant Magnetoelectric Effect in Layered Heterostructures

The dependence of the resonant direct magnetoelectric effect on temperature is studied experimentally in planar composite structures. Samples of rectangular shapes with dimensions of 5 mm × 20 mm employed ferromagnetic layers of either an amorphous (metallic glass) alloy or nickel with a thickness of 20–200 μm and piezoelectric layers of single crystalline langatate material or lead zirconate titanate piezoelectric ceramics with a thickness of 500 μm. The temperature of the samples was varied in a range between 120 and 390 K by blowing a gaseous nitrogen stream around them. It is shown that the effective characteristics of the magnetoelectric effect—such as the mechanical resonance frequency fr, the quality factor Q and the magnitude of the magnetoelectric coefficient αE at the resonance frequency—are contingent on temperature. The interrelations between the temperature changes of the characteristics of the magnetoelectric effect and the temperature variations of the following material parameters—Young’s modulus Y, the acoustic quality factor of individual layers, the dielectric constant ε, the piezoelectric modulus d of the piezoelectric layer as well as the piezomagnetic coefficients λ(n) of the ferromagnetic layer—are established. The effect of temperature on the characteristics of the nonlinear magnetoelectric effect is observed for the first time. The results can be useful for designing magnetoelectric heterostructures with specified temperature characteristics, in particular, for the development of thermally stabilized magnetoelectric devices

Spectroscopy of OSSO and Other Sulfur Compounds Thought to be Present in the Venus Atmosphere

The spectroscopy of cis-OSSO and trans-OSSO is explored and put into the context of the Venusian atmosphere, along with other sulfur compounds potentially present there, namely, S₂O, C₁-S₂O₂, trigonal-S₂O₂, and S₃. UV-vis spectra were calculated using the nuclear ensemble approach. The calculated OSSO spectra are shown to match well with the 320-400 nm near-UV absorption previously measured on Venus, and we discuss the challenges of assigning OSSO as the Venusian near-UV absorber. The largest source of uncertainty is getting accurate concentrations of sulfur monoxide (³SO) in the upper cloud layer of Venus (60-70 km altitude) since the ³SO self-reaction is what causes cis- and trans-OSSO to form. Additionally, we employed the matrix-isolation technique to trap OSSO formed by microwave discharging a gas mixture of argon and SO₂ and then depositing the mixture onto a cold window (6-12 K). Anharmonic vibrational transition frequencies and intensities were calculated at the coupled cluster level to corroborate the matrix-isolation FTIR spectra. The computationally calculated UV-vis and experimentally recorded IR spectra presented in this work aid future attempts at detecting these sulfur compounds in the Venusian atmosphere

Perennial changes and distribution of resources the main species of hunting animals of Russian

The paper presents the assessment of the state in numbers, distribution on the territory and trends of the dynamics at the turn of XX-XXI centuries of the most economically important species of hunting resources in Russia. Materials were obtained on the basis of data questionnaire of «harvest» Services of VNIIOZ which has no analogues in the world on the scale of the covered by territory and the duration of observations (over 80 years) and the analysis of cause-effect relationships of population dynamics. The distribution is shown of the hunting resources by the Federal districts of the country. Predictions of further changes in the number are given by separate species. In the period 1996 to 2015 in Russia it was observed a significant increase in resources of moose, wild boar, roe deer, fox, beaver, a slight increase - in bear, sable, hazel grouse. Reduced in resources is observed in hare, lynx, and in the last five years - in martens. Relatively stable populations are remained in wolf, marmots, wood grouse. Among the ungulates state is alarming in resources of wild boar on some territories in connection with the African swine fever (ASF). The number of wild boar is decreased catastrophically in the Southern and North Caucasian federal districts in connection with the ASF. The current unfavorable situation caused by the ASF may lead to decrease in the number of specie in large parts of the country. Recently, it is observed decrease in interest to hunting on the fur species. The only species which enjoys demand on the international market is sable whose resources over the last two decades remain high with the trend of short stature as a result of ongoing relocation of species. The largest resources of most species of game animals possess the Siberian, Far East and North-West federal districts of the country

Results of Measurements with the Planetary Fourier Spectrometer onboard Mars Express : Clouds and Dust at the End of Southern Summer. A Comparison with OMEGA Images

reserved25mixedL.V. Zasova, V. Formisano, V.I. Moroz, J.-P. Bibring, D. Grassi, N.I. Ignatiev, M. Giuranna, G. Bellucci, F. Altieri, M. Blecka, V.N. Gnedykh, A.V. Grigoriev, E. Lellouch, A. Mattana, A. Maturilli, B.E. Moshkin, Yu.V. Nikolsky, D.V. Patsaev, G. Piccioni, M. Ratai, B. Saggin, S. Fonti, I.V. Khatuntsev, H. Hirsh, A.P. EkonomovZasova, L. V.; Formisano, V.; Moroz, V. I.; Bibring, J. -P.; Grassi, D.; Ignatiev, N. I.; Giuranna, M.; Bellucci, G.; Altieri, F.; Blecka, M.; Gnedykh, V. N.; Grigoriev, A. V.; Lellouch, E.; Mattana, A.; Maturilli, A.; Moshkin, B. E.; Nikolsky, Yu. V.; Patsaev, D. V.; Piccioni, G.; Ratai, M.; Saggin, B.; Fonti, S.; Khatuntsev, I. V.; Hirsh, H.; Ekonomov, A. P