The zonal circulation in the atmosphere of Venus is investigated. As a result of reprocessing the infrared Fourier spectrometry data aboard the Venera-15 spacecraft, three-dimensional fields of the thermal wind are obtained in the coordinates latitude-altitude-solar longitude. A midlatitude jet located near the upper boundary of clouds is the main feature of the thermal wind fields. It is shown that the wind velocity in the jet is variable with time. These variations are solar-related and can be represented by superposition of cosines with periods of 1, 1/2, 1/3, and 1/4 of a Venusian day. The semidiurnal mode of the thermal tide has the highest amplitude. In the midlatitude jet, the wind velocity reaches its maximum value of 115 m/s at about 9 a.m in the second symmetrical maximum, at 9 p.m., the wind velocity is 7-10 m/s lower. A minimum velocity of 90 m/s is observed in the afternoon. On the night side, the wind velocity is systematically lower than on the dayside (by about 10 m/s). Along with changing wind velocity, the midlatitude jet changes its position: latitude (from 45 degrees to 65 degrees) and altitude (from 70 to 65 km). A con elation between the velocity of wind in the midlatitude jet and the jet position was discovered, which is indicative of the angular momentum and flux being conserved when the jet changes its position. In a single observation for the southern hemisphere, a low-latitude jet was discovered. It is observed at a latitude of 10 degrees and altitude of about 80 km, more than 10 km higher than the upper boundary of the clouds with a maximum wind velocity of about 160 m/s.

The evolution of the variances of atmospheric pressure pulsations within the spectral ranges 1-3, 3-5, 5-10, and 10-17 min is analyzed from the observational data that were obtained at the high-rise meteorological tower of the Institute of Experimental Meteorology (Obninsk) in June-July 1996 by means of a precision pressure sensor developed at the Institute for Space Research, Russian Academy of Sciences. It is found that a sharp increase in these pulsations occurs rather frequently and accompanies such atmospheric phenomena as gravity waves, thunderstorms, microfonts, local atmospheric disturbances, etc. The result of particular interest is the revelation of the diurnal course of the variance of mesoscale pressure pulsations (of periods from 1 to 3 min first) with amplitude changes of five to ten times and with its maximum at 13:00 to 15:00 local time. These changes are assumed to be caused by the influence of the lower atmospheric layer, where the diurnal course of wind velocity and thermal stability takes place.

We represent here our report on the remote study of the Martian atmosphere near the surface by a compact aerosol diode lidar during the Mars Surveyor Lander-98 mission. We are planning to study the daily and seasonal variations of the vertical structure of the atmosphere near the surface, both in active and passive mode. In passive mode, the lidar will measure:1) sky brightness by basic receiving channel;2) sky brightness in polarization plane of additional receiving channel.In active mode, the lidar measures the vertical profile of the atmospheric backscatter coefficient.

For studies of internal gravity waves (IGWs), a three-dimensional research site incorporating a PC and measuring equipment (32 probes) placed on and around the tower was created on the basis of the high-rise meteorological tower of the Institute of Experimental Meteorology (IEM), Obninsk, Russia. Pressure measurements were carried out with three differential pressure pulsation probes spaced apart in the horizontal plane and two vertically separated deformation pressure indicators designed at the Institute for Space Research, Russian Academy of Sciences. Regular measurements have been carried out during October-November, They resulted in a large body of material appropriate for solving various problems. The material is partially processed. The IGWs observed in October-November had periods down to several minutes and occurred predominantly for average wind characterized by a nonzero northern component. The IGWs and related small-scale turbulence are shown to be correlated.

Analysis of results obtained by the infrared spectrometer experiment on the Venera 15 orbiter provided a set of new data that should be incorporated in the new VIRA. It consist of vertical profiles of temperature and aerosol content (latitudinally dependent) between the heights of 55 – 95 km, the latitudinal variation of thermal radiation (spectra and fluxes), thermal winds,and SO2 concentration in the upper clouds. Important information can be also obtained from the results of the in situ meteorological measurements with the VEGA balloons and descent probes; such as temperature/pressure profiles, winds, turbulence, and aerosol content.

Fourier spectrometers aboard the Venera 15 and 16 orbiters measured the outgoing spectral radiance of Venus in the 250–1600-cm−1 (Venera 15) and 400–1600-cm−1 (Venera 16) regions with a spectral resolution of 5–7 cm−1 depending on the data handling procedure. This paper gives a short description of the experimental design and discusses those aspects that can be suitably tackled by wide range spectral measurements. Different Venusian regions can be characterized by typical and significantly different radiance and brightness temperature spectra based on the magnitude of brightness temperatures and also on secondary spectral signatures caused by H2SO4 bands as well as isotopic and hot CO2 bands. At least five groups can be identified, one typical for equatorial regions, one for mid-latitudes, and three for the subpolar and polar regions. Estimates of H2O and SO2 abundances were obtained (∼30 ppm at 58 km and ∼2 ppm at 65 km, respectively). SO2 is first identified in the infrared by our measurements. A detailed comparison between computed and measured spectra for the transition zone between mid-latitudes and the cold subpolar region gives arguments that the cloud top is situated within the temperature inversion and not above or below it.