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1.
On the basis of observational data on daily mean surface air temperature (SAT) and sea ice concentration (SIC) in the Barents Sea (BS), the characteristics of strong positive and negative winter SAT anomalies in Moscow have been studied in comparison with BS SIC data obtained in 1949–2016. An analysis of surface backward trajectories of air-particle motions has revealed the most probable paths of both cold and warm air invasions into Moscow and located regions that mostly affect strong winter SAT anomalies in Moscow. Atmospheric circulation anomalies that cause strong winter SAT anomalies in Moscow have been revealed. Changes in the ways of both cold and warm air invasions have been found, as well as an increase in the frequency of blocking anticyclones in 2005–2016 when compared to 1970–1999. The results suggest that a winter SIC decrease in the BS in 2005–2016 affects strong winter SAT anomalies in Moscow due to an increase in the frequency of occurrence of blocking anticyclones to the south of and over the BS.  相似文献   

2.
We have estimated and compensated the error in long-term series of the aerosol optical thickness (AOT) calculated from the data on direct integral solar radiation measured by a standard actinometer at the Meteorological Observatory of the Moscow State University (MO MSU) for strong atmospheric turbidity conditions. The necessary corrections have been obtained by the Monte-Carlo simulation of the actinometry measurements for different atmospheric conditions, taking into account the angular size of the field of view of the instrument; and a special correctional formula has been obtained. This correction formula has been applied for all timed AOT values of above 0.5 observed at the MO MSU for the entire time period from 1955 to 2013. Changes in the long-term average AOT values in Moscow occurred only when the smoky haze from the forest and peat fires affected the aerosol turbidity of the atmosphere. Here, the significant decreasing trend of aerosol optical depth of the atmosphere from 1955 to 2013 has been retained with the same confidence level.  相似文献   

3.
The microphysical characteristics of aerosol were measured in the atmospheric surface layer simultaneously over the center of Moscow and its vicinity (Zvenigorod Scientific Station, Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences) from June 15 to June 30, 2009, in order to compare the mass concentrations, particle-size distribution functions, and elemental compositions of aerosol over the megapolis and the background zone. During the fire peak of 2010, on August 8, aerosol samples were taken in the center of Moscow and their chemical composition was determined. Comparing results obtained from the simultaneous measurements of the concentrations of aerosol and its elemental composition made it possible to determine their interdiurnal variability, which suggests that the features of time variations are of a regional character and they are determined mainly by the dynamics of the synoptical processes of air-mass exchange. The chemical composition of obtained samples was determined using the method of atomic absorption spectrometry. The measurement results obtained in June 2009 revealed an increase in the content of anthropogenic elements in the atmosphere over Moscow when compared to their content in the atmosphere over the background zone. In Moscow, during the summer fires of 2010, the concentration of sulfur exceeded its concentration in June 2009 by an order of magnitude, and the concentrations of Na, Mg, Al, Si, K, Ca, and Fe increased several times. The mean mass concentration of aerosol amounted to 917 μg/m3 in August 2010 and 50–70 μg/m3 in June 2009.  相似文献   

4.
Izvestiya, Atmospheric and Oceanic Physics - Seasonal differences in the Moscow urban heat-island intensity (UHII) have been studied in detail based on data obtained in 2018–2020 by the...  相似文献   

5.
We performed a correlation and spectral analysis of time series of data on epizootics, epidemics, and famine in Siberia and Mongolia. We have found that periods T of approximately 100 years prevail in their structures, which are also typical for time series of solar activity.  相似文献   

6.
依据构造样式和沉积特征将济阳坳陷陡坡带分为板式、铲式、断阶式、坡坪式4种类型。断阶式和坡坪式陡坡带砂砾岩扇体类型多,成藏条件优越,各类油气藏发育完全,在纵向上组成较完整的油气藏序列。板式和铲式陡坡带砂砾岩扇体主要为近岸水下扇,其次为扇三角洲,油气藏类型单一,在纵向上油气藏序列发育也不完整。此外,板式陡坡带由于断裂不发育,沉积相带窄,油气相对贫瘠。油气在断阶式中最为富集,其次为坡坪式和板式,铲式相对贫乏。  相似文献   

7.
Phenylalkanes with carbon numbers between 16 and 19, characterized by the main carbon-18, have been identified in the modern sediments collected from gas hydrate area from the Gulf of Mexico. The structure of phenylalkanes with four isomers for every carbon number was determined by means of their mass spectra and previous studies. The distribution of the series characterized by a low molecular mass was similar to the distribution of n-alkane, alkylcyclohexanes and alkylbenzenes in each sample. There were differences in the distribution of the phenylalkane series between the S - 1, S - 4, S - 7, S - 9 samples and the S - 8, S - 10 and S - 11 samples. The phenylalkanes might be derived from Archaea associated with anaerobic oxidation of methane （AOM） processes in S - 1, S -4, S -7 and S -9 samples according to their distribution resembled with the distribution of the extract from a type of Archaea. The distribution of alkylcyclohexanes and alkylbenzenes in S - 1, S - 4, S - 7 and S - 9 sample was found to be similar to each other. The odd-over-even predominance of alkylcyclohexanes was seen as the input of some bac- terial.  相似文献   

8.
Based on observations of carbon monoxide (CO) concentrations at three Mosekomonitoring stations, we have analyzed the weekly cycle of CO in the surface air of Moscow in 2004–2007. At all stations the minimum long-term mean daily CO values are observed on Sunday. The weekly cycle of CO more clearly manifests itself at the center of Moscow and becomes less clear closer to the outskirts. We have analyzed the reproducibility of the weekly cycle of CO from one year to another, the seasonal dependence, its specific features at different times of day, and the changes in the diurnal cycle of CO during the week. The factors responsible for specific features of the evolution of surface CO concentrations at different observation stations have been analyzed. The empirical probability density functions of CO concentrations on weekdays and at week- end are presented. The regularity of the occurrence of the weekend effect in CO has been investigated and the possible reasons for breaks in weekly cycles have been analyzed. The Kruskal-Wallis test was used to study the statistical significance of intraweek differences in surface CO contents.  相似文献   

9.
The results of the carbon monoxide total content measurements over Moscow and Zvenigorod for 2005–2008 are compared with the same data sets for Moscow 1986–2005 and Beijing, 1992–2007. Two identical medium resolution diffraction spectrometers (resolution 0.2 cm?1) with solar tracking system were used. The CO total content measured simultaneously over the city and over Zvenigorod Scientific Station (ZSS) of the Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (60 km west from Moscow). This method allows to isolate an urban part of CO content. The acoustic locator SODAR LATAN-3 measurements permitted us to study the influence of the carbon monoxide ventilation conditions upon level of pollution. Correlation coefficients between the urban part of CO content and average wind speed for cold and warm seasons were obtained. The data sets analysis showed a preeminent effect of the wind within boundary layer (up to 300 m) over the CO ventilation. The urban part of the CO content hasn’t increased in spite of more than quintuple increase of the motor-vehicles number in Moscow. An increase of the rural CO total column for the 1970–1985 has transformed into its virtually stable amount in between of 1986 to 2000, changed then to a decrease for 2001–2008. We noted the 2008 as “the year of the CO total column minimum” over the past decade. The effect of urban CO sources influence on the CO total column in rural area is small, i.e. on a level of 3% of the total number of measurements. The number of extremal daily values for Moscow is estimated as 5%, and 20% for Beijing.  相似文献   

10.
We analyzed measurements of the total carbon monoxide (CO) content in the atmosphere in the region of St. Petersburg (59.88°N, 29.83° E; 20 m above sea level) in the period from 1995 to 2009. The average annual behavior for the entire measurement period has a maximum in February–March and a minimum in July with an amplitude of ～20%. In the absence of strong forest fires in the European part of the Russian Federation and Siberia, the annual minimum of the total CO content is usually recorded in August–September. In winter 1995–2009 (November–January), there was a decrease in the total CO content with a gradual shift in the maximum of the annual behavior from January (1995–1999) to February (2000–2004) and March (2005–2009). The total CO content in January–February 2009 was ～20% lower than the multiyear average level. Estimates of the linear trend for the maximum, minimum, and average values for the period of 1996–2009 showed an absence of statistically significant long-term changes in the total CO content. A spectral analysis of data showed that the spectral components with periods of 12, 14, 17, 24, and 46 months are extracted with 80% confidence. It is shown that the irregular component of the time series of the total CO content (calculated for the period from May to September) agrees well with data on the areas of the forest fires and on the volume of the burnt forest and that 1999, 2001, 2005, 2007, and 2009 can be considered “background” years with the least numbers of forest fires.  相似文献   

11.
We analyze spatial variations in the air turbidity factor T obtained from the interpolation of ground-based solar radiometry data within the territory (40°–70° N, 30°–60° E) in summer 2010. The abnormal heat and connected fires of summer 2010 changed the mean values of air turbidity and the character of its spatial variations. As a result, a “tongue” of increased values of the turbidity factor was observed in the south-to-north direction in July, and a closed region of anomalous high T was formed over the territory (48°–55° N, 37°–42° E) to the south of Moscow and partly covered the Moscow region in August. Such a pattern resulted from blockage preventing from ingress of air masses from the west and producing closed air circulation over the European Part of Russia (EPR).  相似文献   

12.
Izvestiya, Atmospheric and Oceanic Physics - Instrumental observation data on acoustic oscillations in Moscow for 2014–2017 have been analyzed. The difference in amplitude and spectral...  相似文献   

13.
Modern climatic changes for 1991–2013 in the lower 4-km layer of the atmosphere in the Moscow region are discussed based on long-term measurements using radiosondes in Dolgoprudny near Moscow and sensors installed on a high mast in Obninsk and on a television tower in Ostankino in Moscow. It is shown that at the end of the 20th century and the beginning of the 21st century the mean-annual air temperature at all heights from 2 to 4000 m increased by an average of 0.1°C per year. In recent years, the warming has slowed. Over the last two decades, long-term changes were multidirectional, depending on the season: warming in May–December, cooling in January–February, and no statistically significant changes in March and April. The probable reason for the temperature decrease in the middle of the cold period is changes in the large-scale atmospheric circulation during recent years (the negative phase of the North Atlantic Oscillation in early 2010s). In recent years, the Moscow region climate continentality has increased because of warming in summer and cooling in winter, despite the secular decreasing trend, which was noted before. Mean daily and annual warming rates in Dolgoprudny were higher than in Obninsk. The probable reason is the northward construction expansion and the strengthening of the Moscow heat island. The highest annual temperature amplitude is recorded at heights of 200–300 m.  相似文献   

14.
The influence that megalopolises have on the atmospheric composition on regional and global scales is the subject of intense investigations; however, data on the emissions of pollutants used for such investigations are often insufficiently reliable. In this work the possibilities for diagnosing long-term changes in nitrogen oxide emissions in megalopolises are investigated based on a combined use of data from satellite measurements and modeling of the tropospheric nitrogen dioxide content. Primary emphasis is placed on analyzing possible situations when emission changes are of a nonlinear character. The proposed methodology includes an original method for the nonlinear approximation of changes in a physical quantity from a noised time series of its measurements. Changes in NO x emissions are investigated in 12 megalopolises of Europe and the Middle East in the period from 1996 to 2008. Statistically significant changes in NO x emissions are detected in five megalopolises (Baghdad, Madrid, Milan, Moscow, and Paris). By using three megalopolises (Madrid, Milan, and Paris) as an example, it is shown that a nonlinear approximation of NO x emission changes agrees better with independent ground-based measurements than an analogous linear approximation.  相似文献   

15.
Long-term (1965–2000) changes of macrozoobenthos and hydrography have been studied in the Gulf of Finland (GoF). For the first time, statistical multivariate time series analysis is applied to Baltic Sea data to verify the relationship between biota and interacting environmental factors causing large-scale hypoxia in the open sea. For macrozoobenthos, a consistent long-term development of the assemblages was found over the study area. In the period before the 1990s, very sparse macrozoobenthos prevailed, followed by a notable expansion of macrofauna between the late 1980s and early 1990s and leading to a maximum of total abundance and species number between 1991 and 1996. After that, a sudden collapse of the communities took place in 1996–1997. The hydrographical changes included a continuous decrease in salinity and density stratification until the early 1990s, after which an increase took place again. In contrast, low mean and minimum dissolved oxygen concentrations were observed at the beginning of the study period, followed by increasing values in the late 1980s and early 1990s, and a simultaneous decline of oxygen conditions in 1996. Based on non-linear trends estimated by dynamic factor analysis (DFA), high and significant correlations were found between total macrofauna abundance, number of species, salinity, oxygen conditions, strength of stratification and freshwater run-off. The results confirm that oxygen is obviously a fundamental factor that determines the state of the macrozoobenthos in the deep GoF, overruling other abiotic factors. However, the improvement of the oxygen conditions is apparently caused by the long-term decrease of salinity and loss of stratification in the relatively shallow GoF, reflecting large-scale changes in hydrography of the Baltic Sea during the long 1977–1993 stagnation period. Thus the development in GoF is opposite to the deeper basins in the central Baltic. We conclude that salinity and stratification are probably linked with climatic variability via freshwater run-off, which may be important in regulating the oxygen conditions and state of macrozoobenthos in GoF.  相似文献   

16.
Several time series in the Norwegian Sea indicate an upper layer decrease in temperature and salinity since the 1960s. Time series from Weather Station “M”, from Russian surveys in the Norwegian Sea, from Icelandic standard sections, and from Scottish and Faroese observations in the Faroe–Shetland area have similar trends and show that most of the Norwegian Sea is affected. The reason is mainly increased freshwater supply from the East Icelandic Current. As a result, temperature and salinity in some of the time series were lower in 1996 than during the Great Salinity Anomaly in the 1970s. There is evidence of strong wind forcing, as the NAO winter index is highly correlated with the lateral extent of the Norwegian Atlantic Current. Circulation of Atlantic water into the western Norwegian and Greenland basins seems to be reduced while circulation of upper layer Arctic and Polar water into the Norwegian Sea has increased. The water-mass structure is further affected in a much wider sense by reduced deep-water formation and enhanced formation of Arctic intermediate waters. A temperature rise in the narrowing Norwegian Atlantic Current is strongest in the north.  相似文献   

17.
Detailed multibeam, sedimentological, and geophysical surveys provide ample new data to confirm that the Anaximander Mountains (Eastern Mediterranean) are an important area for active mud volcanism and gas hydrate formation. More than 3000 km of multibeam track length was acquired during two recent missions and 80 gravity and box cores were recovered. Morphology and backscatter data of the study area have better resolution than previous surveys, and very detailed morphology maps have been made of the known targeted mud volcanoes (Amsterdam, Kazan and Kula), especially the Amsterdam “crater” and the related mud breccia flows. Gas hydrates collected repeatedly from a large area of Amsterdam mud volcano at a sub-bottom depth of around 0.3–1.5 m resemble compacted snow and have a rather flaky form. New gas hydrate sites were found at Amsterdam mud volcano, including the mud flow sloping off to the south. Gas hydrates sampled for the first time at Kazan mud volcano are dispersed throughout the core samples deeper than 0.3 m and display a ‘rice’-like appearance. Relative chronology and AMS dating of interbedded pelagic sediments (Late Holocene hemipelagic, sapropel layer S1 and ash layers) within the mud flows indicate that successive eruptions of Kula mud volcano have a periodicity of about 5–10 kyrs. New mud volcanoes identified on the basis of multibeam backscatter intensity were sampled, documented as active and named “Athina” and “Thessaloniki”. Gas hydrates were sampled also in Thessaloniki mud volcano, the shallowest (1264 m) among all the active Mediterranean sites, at the boundary of the gas hydrate stability zone. Biostratigraphical analyses of mud breccia clasts indicated that the source of the subsurface sedimentary sequences consists of Late Cretaceous limestones, Paleocene siliciclastic rocks, Eocene biogenic limestones and Miocene mudstones. Rough estimations of the total capacity of the Anaximander mud volcanoes in methane gas are 2.56–6.40 km3.  相似文献   

18.
Temporal variations in the surface concentrations of two greenhouse gases (carbon dioxide and methane) in the atmosphere over a large city are studied on the basis of the data obtained during the 2003–2005 observations at a Moscow station for environmental monitoring. This station is based on the TROICA mobile observatory and located at the meteorological station of the Faculty of Geography, Moscow State University, on Vorob’evy gory. The methods of isolating the background concentrations of greenhouse gases under urban conditions are proposed, and the excess concentrations of CO2 and CH4 over their background values are estimated for different seasons and times of day. The CO2 and CH4 concentrations are shown to have more pronounced diurnal cycles in summer than in winter. The main causes of temporal variations in the surface concentrations of CO2 and CH4 under urban conditions and the differences between the mean concentrations of these greenhouse gases in Moscow and other areas of Russia are analyzed. It is shown that variations in the surface concentrations of carbon dioxide and methane on different time scales are caused by different atmospheric processes (global circulation, mesoscale gravity waves, surface temperature inversions, etc.)  相似文献   

19.
Self-aeration in high-speed free surface flows occurs commonly and is of interest to ocean engineering, hydraulic engineering, and environmental engineering. For two-phase air–water flows, macroscopic air–water flow properties develop gradually, accompanied by the change of microscopic air–water structures. In this article, representational experimental studies on macroscopic and microscopic characteristics of self-aerated open-channel flows are summarized and compared. The isolated effect of the flow Reynolds number and air quantity on the differences in air count rate and chord size are analyzed and discussed. The results show that the characterized flow depth y50, affected by the turbulence transfer, is a specific criterion to distinguish the interior air–water structure development. Two distinct linear trends of self-aeration are found, depending on the y50/y90 variation with a breaking point at Cmean = 0.50. The air count rate and size scale in self-aerated flows are affected by the air quantity of self-aerated flows, even with identical flow Reynolds numbers. Thus, a specific parameter is proposed to assess the air–water structures and a series of self-similarity relationships in self-aeration properties are obtained. The link between macroscopic and microscopic air–water properties results in significant scale effect on air–water structures in self-aerated flows.  相似文献   

20.
This paper reports on growth of the Boulders colony of African penguins Spheniscus demersus from inception in 1985 to the present. More than 900 pairs now breed there. Growth of the colony slowed in 1995 and 1996 and reversed in 1998, coinciding with periods of low abundance of Cape anchovy Engraulis capensis off South Africa. In December 1996, penguins were excluded from a portion of land where they had formerly bred. They responded by increasing the density of their nests in other areas and expanding their area of breeding longshore. These patterns indicate that food and not space are currently controlling colony growth rate. Much of the colony growth probably results from immigration of first-time breeders from other colonies. Of immigrants, 70–80% may be from Dyer Island to the south-east, where numbers of penguins have decreased. Boulders also is frequently visited by penguins from other colonies, and by rehabilitated birds.  相似文献   

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