Analysis of Changes in the Ice Cover of Freshwater Lakes by SMOS data     

Tikhonov  V. V.  Khvostov  I. V.  Romanov  A. N.  Sharkov  E. A. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(9):1135-1140

Izvestiya, Atmospheric and Oceanic Physics - This paper presents an analysis of seasonal variations in the brightness temperature of large freshwater lakes (Baikal, Ladoga, Great Bear, and Huron)...  相似文献   

Features of the Intrinsic L-Band Radiation of the Gulf of Ob during the Freeze-Up Period     

Tikhonov  V. V.  Khvostov  I. V.  Romanov  A. N.  Sharkov  E. A.  Boyarskii  D. A.  Komarova  N. Yu.  Sinitskiy  A. I. 《Izvestiya Atmospheric and Oceanic Physics》2020,56(9):936-949

Izvestiya, Atmospheric and Oceanic Physics - This article analyzes seasonal and interannual dependences of brightness temperature in different zones of the Gulf of Ob according to data from the...  相似文献   

A new formula for saturated water steam pressure within the temperature range −25 to 220°C     

N. P. Romanov 《Izvestiya Atmospheric and Oceanic Physics》2009,45(6):799-804

Instead of approximation formula ln(E(t)/E(0)) = [(a ? bt)t/(c + T)] commonly used at present for representing dependence of pressure of saturated streams of liquid water E upon temperature we suggested new approximation formula of greater accuracy in the form ln(E(t)/E(0)) = [(A ? Bt + Ct ²)t/T], where t and T are temperature in °C and K respectively. For this formula with parameters A = 19.846, B = 8.97 × 10^?3, C = 1.248 × 10^?5 and E(0) = 6.1121 GPa with ITS-90 temperature scale and for temperature range from 0°C to 110°C relative difference of approximation applying six parameter formula by W. Wagner and A. Pruß 2002, developed for positive temperatures, is less than 0.005%, that is approximately 15 times less than accuracy obtained with the firs formula. Increase of temperature range results in relative difference increasing, but for even temperature range from 0°C to 220°C it does not higher than 0.1%. For negative temperatures relative difference between our formula and a formula of D. M. Murphy and T. Koop, 2005, is less than 0.1% for temperatures higher than ?25°C. This paper also presents values of coefficients for approximation of Goff and Grach formula recommended by IMO. The procedure of finding dew point T _d for known water steam pressure e _n based on our formula adds up to solving an algebraic equation of a third degree, which coefficients are presented in this paper. For simplifying this procedure this paper also includes approximation ratio applying a coefficient A noted above, in the form T _d (e _n ) = \(\frac{{AT_0 }}{{A - \varepsilon }}\) + 0.0866?² + 0.0116?^10/3, where ? = ln(e _n /E(T ₀)). Error of dew point recovery in this ratio is less than 0.005 K within the range from 0 to 50°C.  相似文献   

Experimental investigation of free (downward) convection near horizontal cold spots     

N. P. Romanov 《Izvestiya Atmospheric and Oceanic Physics》2009,45(3):332-345

To explain the conditions for dew and pollutant precipitation during still-weather radiative cooling of the Earth’s surface, attention is paid to the role of surface temperature inhomogeneities and convective air flows appearing near them. To understand how convection forms near cold spots, schematic cylinders with adiabatic walls and a cold bottom are considered. The results of this consideration agree with the results obtained in previous calculations and experimental studies, namely, the Nusselt number depends on the Rayleigh number to the power 1/5 with the proportionality coefficient γ. The quantitative characteristics were experimentally investigated by measuring the vertical temperature profiles and observing tracer motion near circular cold water surfaces about 30 cm and 10 m in size. As a result, it is found that, for isolated planar spots, the temperature difference between the spot surface and the environment decreases in accordance with the exponential law and air motions from the center of the spot toward its edges are of a laminar character. For the Rayleigh numbers that use the ratio of the area of the spot to the half of its perimeter as the characteristic size, the mean values of the coefficient γ are 1.1 for an isolated spot with Ra = 10⁶ and 0.7–0.8 for spots with Ra = 10⁶?5 × 10¹⁰ located at one level with the surrounding surface. For deepened spots, the processes of heat exchange significantly slow down and the character of temperature profiles changes depending on the material of the surrounding walls. The process of establishing the equilibrium temperature of an isolated spot that is caused by radiative cooling and the convective inflow of heat and moisture is considered in the Appendix. A method for preventing radiation fog by air drying during convection near the surrounding cold surfaces is proposed, and the principles of the intensification of the condensed-moisture collection are formulated.  相似文献   

Influence of a tropical cyclone on the upper ionosphere according to tomography sounding data over Sakhalin Island in November 2007     

L. B. Vanina-Dart  A. A. Romanov  E. A. Sharkov 《Geomagnetism and Aeronomy》2011,51(6):774-782

Tomography sounding data for the first half of November 2007 are presented. The sounding was conducted over three points located at the same meridian—Yuzhno-Sakhalinsk (47° N, 143° E), Poronaisk (49° N, 143° E), and Nogliki (51° N, 143° E)—in order to find the possible influence of a tropical cyclone on the upper ionosphere. A change in the foF2 parameter by on average no more than 10–20% is a possible response of the upper ionosphere localized over the tropical cyclone (TC) zone (in the given case, 25°–30° northward and 5°–20° eastward) at a distance of approximately 3800–5500 km from it. A decrease or, vice versa, an increase in foF2 is related to the delay of the measurement moment relative to the beginning of the TC action. The complexity of a morphological analysis of the given event is that a tropical cyclone is a “wideband” (in the longitudinal and, to a lesser degree, in the latitudinal directions) and lasting disturbance source.  相似文献   

Monitoring the carbon dioxide mixing ratio in the troposphere and the methane total column over Siberia according to the data of the AIRS and IASI IR sounders     

A. B. Uspensky  A. V. Kukharsky  S. V. Romanov  A. N. Rublev 《Izvestiya Atmospheric and Oceanic Physics》2011,47(9):1097-1103

The development of the AIRS (EOS/Aqua) and IASI (MetOp) satellite hyperspectral IR sounders opens new opportunities for determining the average tropospheric carbon dioxide concentration (X_CO2 X_{CO_2 } ) and total methane content (Q_CH4 Q_{CH_4 } ) in the atmosphere from large distances, which is important in climatic studies and since the ground network for CO₂ and CH₄ observations is scarce. The improved scheme for X_CO2 X_{CO_2 } retrieval from the AIRS data, which was used to construct the X_CO2 X_{CO_2 } spatial distribution based on the AIRS data for July 2003 and 2010 covering Siberia, is presented. A similar methodology was also used to retrieve instantaneous X_CO2 X_{CO_2 } values from the cloud-cleared IASI data for July 7, 2008 and the YAK-AEROSIB experimental region. A comparison of the satellite data with quasi-synchronous aircraft observations gives an error of about 2.2 million⁻¹. The iterative physical algorithm was developed in order to retrieve Q_CH4 Q_{CH_4 } . The efficiency of the proposed algorithm was estimated during the experiments with actual IASI data covering the Siberian region during several days in July 2008. The Q_CH4 Q_{CH_4 } estimates were validated by comparing them with the spatially superimposed and quasi-synchronous Q_CH4 Q_{CH_4 } , estimates based on the AIRS data. The standard deviations of both types of estimates are not more than 3%.  相似文献   

Statistical significance and climatic role of the Global Atmospheric Oscillation     

V. I. Byshev  V. G. Neiman  Yu. A. Romanov  I. V. Serykh  D. M. Sonechkin 《Oceanology》2016,56(2):165-171

The statistical significance of Global Atmospheric Oscillation (GAO), whose main element is the well-known El Niño–Southern Oscillation in the equatorial Pacific, was assessed from monthly mean atmospheric pressure data at sea level at the nodes of a regular 5° × 5° grid covering the entire surface of the Earth. The data were collected in 1920–2012. It was found that statistically reliable GAO signals cover almost the entire tropical zone and they also appear at mid- and high latitudes of both hemispheres.  相似文献   

Relations between the Chemical Composition of Organic Matter in Lacustrine Ecosystems and the Genesis of Their Sapropel     

O. P. Taran  V. V. Boltenkov  N. I. Ermolaeva  E. Yu. Zarubina  I. V. Delii  R. E. Romanov  V. D. Strakhovenko 《Geochemistry International》2018,56(3):256-265

The paper presents data on sapropels from ten lacustrine systems at the Barabinsk and Kulunda plains in Novosibirsk region. The sapropels are classified according to the type of the biological contribution to their origin and the content of organic matter. The sapropel of lakes Kachkulnya and Barchin, which are rich in organic matter and differ by the type of their origin (macrophytogenic and planktonogenic), were studied in much detail with the application of the following techniques: X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), and elemental (CHNSO) analysis. Groups of organic compounds contained in the organic matter were determined by successive extraction, and the monosaccharide composition was studied by high-performance liquid chromatography (HPLC). The organic matter of sapropel with different type of boilogical contribution was discovered to differ in elemental (CHNSO) composition, group of organics, and the monosaccharide compositions. Our results led us to conclude that the genesis of sapropel significnalty imprints the composition of its organic matter.  相似文献   

Potential models of the unipolar sunspot magnetic field     

V. V. Denisenko  V. A. Kotov  V. A. Romanov  V. S. Sokolov 《Solar physics》1982,81(2):217-229

The potential models of the unipolar sunspot magnetic field are calculated on the basis of magnetographic measurements of the magnetic field made in the three spectral lines of different intensities, H, Cai 6103 and Fei 4808. The computed distributions of the magnetic field vector are compared with actual distributions observed at these three levels. It is shown that the electric current density in the spot reaches values up to 10⁵ CGSE in the volume contained between formation depths of two pairs of lines, Fei 4808-Cai 6103 and Fei 4808 - H. Therefore, the magnetic field of the spot deviates strongly from a potential configuration. To the contrary, at higher levels, in the semi-infinite volume restricted at the bottom by the hydrogen H-line, the field appears to be quite close to a potential one.  相似文献   

Determination of the chlorophyll-a concentration vertical profile by the spectra of incident solar radiation in the ocean     

S. V. Bushnev  E. V. Myasnikov  N. B. Nikolaeva  A. A. Romanov 《Physical Oceanography》1994,5(4):287-293

Methods of rapid analysis of the chlorophyll-a concentration vertical profile by the spectra of incident solar radiation are suggested. The methods are applicable for the ocean layerz=20–80 m containing waters of type 1 (by Morel's classification). Testing of the methods underin situ conditions showed that they can be used to reconstructC _ch(z) profiles, with a relative error of 10% and a root-meansquare error of 20–30% at most, provided the data are calibrated using field observations conducted at two or three sites in the test area.Translated by Vladimir A. Puchkin.  相似文献