A conservative form of the deep convection equations and the efficiency of heat energy conversion in a polytropic mantle model

A wide class of equations is defined for a high pressure and subcritical temperature range of a fluid state whose thermodynamic properties enable the construction of a polytropic model of the mantle. A variant of deep convection equations of the Ogura and Phillips type is substantiated in terms of the polytropic mantle model. The proposed system of the deep convection equations includes fluctuation of the generalized potential temperature, has a quasi-incompressible form, and is transformed into Mihaljan’s system of shallow convection equations with a decrease in the layer depth. This circumstance is of great importance because it validates the use of the same dimensionless parameters as in the shallow convection model. The advantage of the proposed variant of the deep convection equations is its complete conservatism, which allows one to gain constraints on the efficiency of energy conversion in deep mantle processes and the thermal energy power expended on the generation rate of the convection kinetic energy and associated processes. This power is shown to be of the order of half the geothermal flux measured on the Earth’s surface.     

Coefficient of horizontal eddy diffusion of a tracer on the water surface as a function of the wave age

A relationship between the statistical parameters of horizontal diffusion and the parameters of the energy-containing part of the frequency spectrum of sea-surface elevations is found depending on the wave age Ω and the ratio between the wind speed at 10 m and the phase velocity of the peak of a wave. It has been observed in [1–7] that the diffusion coefficient K(r) of a patch of size r increases as r ^β, where 1.15 < β < 4/3, and the patch area S(t) increases with time as t ^γ, where 2 < γ < 3. As was calculated in [15], in the energy-containing part of the elevation frequency spectrum, S(ω) ～ ω^?n , where n = 13/3 for young waves with Ω > 2, n = 4 for waves with 1.2 < ψ < 2, and n = 11/3 for developed waves with 0.83 < Ω < 1.2. It is found that β = (n + 1)/4 and γ = 8/(7 ? n). These relations explain the entire set of observed exponents: β = 4/3 and γ = 3 for young waves and β = 1.15 and γ = 2.34 for large sizes (up to 1000 km) and times (up to a month) when it is found here that β = 7/6 and γ = 2.4.     

Relationship of the Long-Period Free Oscillations of the Earth with Atmospheric Processes

Doklady Earth Sciences - Based on the five-year record of the superconducting gravimeter in Strasburg (48.6° N, 7.7° E), the correlation is calculated between the long-period free...     

Observations of the Atmospheric Composition over Russia: TROICA Experiments

Izvestiya, Atmospheric and Oceanic Physics - Results obtained in the course of unique observations (as part of the TROICA project) of the composition and state of the atmosphere over Russia have...     

Current issues in the study and quality assessment of drinking groundwater

The state of the regulatory environment for assessing the quality of fresh groundwater used for domestic water supply is characterized. The geochemistry of fresh groundwater deposits, the hydrogeochemistry of standardized microelements (boron, bromine, lithium), and technogenic processes are described. The regional features of fresh groundwater deposits are characterized.     

Laws of Random Walks Derived by A.N. Kolmogorov in 1934

In the first half of the 1930s A.N. Kolmogorov was developing analytical methods for the probability theory and presented the solution of the Fokker–Planck type equation. This solution contains scales for the distribution function moments of the mean squares for velocities and relative displacements of the analyzed objects and for the mixed moments of velocities and coordinates. The exclusion of time from these moments leads to the 2/3 law for the velocity structure function and to the Richardson–Obukhov law for the eddy diffusion. The analysis of the fetch laws for wind waves demonstrates that the Kolmogorov laws are manifested in the growth of wave amplitudes and in the form of elevation spectra. These laws also work in the statistics of the planetary surface relief, in the size distribution of the lithospheric plates, in the energy spectra of cosmic rays, and in other processes. In the equation deduced in 1934, probability distribution functions are derived only under the condition of homogeneity of these functions and thereby allow describing a broad range of phenomena and processes.     

Trace Gas Measurements Between Moscow and Vladivostok Using the Trans-Siberian Railroad

Using a laboratory wagon traveling along the Trans-Siberian railroad, O₃, NO, NO₂, CO, CH₄, SF₆ and black carbon aerosol have been measured during the summer of 1996. The expedition from Niznij Novgorod (500 km east of Moscow) to Vladivostok (and back to Moscow) has shown the great potential of the train method; here the first results are presented and discussed. A wealth of boundary layer air data was obtained during the over 18000 km travel without serious contamination problems from the electric train itself. The diurnal O₃ cycle peaked generally below 50 nmole/mole, showed the effects of changes in J(NO₂), and often dropped to a few nmole/mole at night time during inversions. Over the vast Siberian lowlands situated between the Ural mountains and the river Yenisey, CH₄ levels were consistently elevated at around 1.95 µmole/mole, which we mainly attribute to wetland emissions. Over eastern Siberia, however, CH₄ levels were generally lower at 1.85 µmole/mole. In contrast, over the west Siberian lowlands, CO levels were relatively low, often reaching values of only 110 nmole/mole, whereas over eastern Siberia CO levels were higher. Very high CO levels were detected over a 2000 km section east of Chita, along the river Amur, which represented an enormous polluted air mass. ¹⁴C analysis performed on several CO samples confirms that the origin was biomass burning. SF₆, which was measured as a general conserved tracer, showed an eastward attenuation from 4.0 to 3.9 pmole/mole, with peaks in a number of places due to local Russian emissions.     

Another look at atmospheric dynamics on Titan and some of its general consequences

Mean wind velocities, U, and horizontal temperature differences, δT, are estimated for the Titan atmosphere using the similarity theory of the author. It is found that U is of order 1 m/sec and δT ～ 0.1 K. The last value agrees with its estimate by Leovy and Pollack (1973, Icarus19, 195–201); however the values of U are an order of magnitude less. While analyzing the causes of the difference it is found that the circulation models developed in I overestimate considerably the atmospheric efficiency in transformation of solar energy into the kinetic energy of motions. Possible reasons for such an overestimate are discussed. We conclude that the efficiency coefficient is a very sensitive characteristic of a circulation regime and that its determination is an efficient means for checking the correspondence of various circulation models with reality. Arguments are presented stressing the conclusion of I that the Titan atmospheric circulation is in the Hadley symmetric regime, which is strongly influenced by the satellite's own rotation. At the same time a thermal tide should be a noticeable feature of the circulation. In the upper part of the Titan atmosphere something like the phenomenon of the 4-day Venus circulation may be developed. It is noted that the analogy between the Titan and Venus atmospheric circulations might be a very close one.