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1.
The emissions from fires in the boreal zone of northern Eurasia significantly contribute to the global emissions of greenhouse gases, their precursors, and aerosols. These emissions are an important component of the global carbon balance, and they significantly affect both seasonal and long-term variations in the chemical composition and radiation properties of the atmosphere on both regional and global scales. The atmospheric emissions of carbon monoxide (CO) from biomass burning have systematically been estimated for the entire territory of northern Eurasia over the period of 2000–2008 on the basis of satellite (MODIS MCD45A1) data on burned vegetation and the Seiler-Crutzen emission model with consideration for both regional and seasonal features. On the whole, for Russia, the annual emissions of CO from biomass burning ranged from 10.6 to 88.2 Mt/y over the indicated period. Depending on fire activity, the atmospheric emissions of CO from natural fires and agricultural work may yield from 25 to 200% of the total technogenic emissions according to the EDGAR-2000 model. In this case, the dominant contribution is made by boreal forest fires (8–57 Mt/y), whose portion amounts to 63–76% of the total emissions from biomass burning. This relatively short observational series does not allow one to reliably estimate long-term variations; however, on the whole, a stable increase in burned areas has been observed in forest, steppe, and agricultural regions over the last decade. Our analysis suggests significant spatial and seasonal variations in the large-scale fields of fire emissions, which are determined by the physical, geographic, and climatic features of individual regions. The calculated fields of emissions can be used in transport-chemical models, studies of the regional transport and quality of air, and climate models.  相似文献   

2.
Satellite measurements of the fire radiation power, measurements of atmospheric pollution in the network of GPU Mosekomonitoring stations, and the modern CHIMERE chemical transport model (CHIMERE CTM) are used for estimating the influence that forest fires have on the air pollution level in the Moscow megalopolis region during the summer of 2007. The method by which the radiation power caused by natural fires determined from satellite measurements is converted into emissions of individual model species is described. General problems related to the optimization of estimates of fire emission and the effects caused by them based on the combined use of measurement data on the composition of the atmosphere and the CTM are considered using a concrete example. It is shown, in particular, that the use of the standard least squares method for the optimization of fire emissions from leads in the general case to obtaining biased (underestimated) estimates. The results of calculations consistent with measurements show that forest fires near Moscow can occasionally be responsible for a considerable part of the air pollution observed in Moscow and its vicinities, and they can be the main reason for the high level of atmospheric pollution in some neighboring regions.  相似文献   

3.
The prediction results of large-scale forest fire development are given for Siberia. To evaluate the fire risks, the Canadian Forest Fire Weather Index System (CFFWIS) and the Russian moisture indices (MI1 and MI2) were compared on the basis of the data of a network of meteorological stations as input weather parameters. Parameters of active fires were detected daily from the NOAA satellite data for the period of 1996–2008. To determine the length of the fire danger season, the snow cover fractions from Terra/MODIS data (2001–2008) were used. The features of fire development on territories with different types of flammable fuel are considered. The statistical analysis of the areas and number of fires typical of each vegetation class is made with the use of the GLC2000 vegetation map. A positive correlation (∼0.45, p < 0.05) between the cumulative area of local fires and the MI1 and Canadian BUI and DMC indices is revealed. The Canadian ISI and FWI indices describe best the diurnal dynamics of fire areas. The above correlations are higher (∼0.62, p < 0.05) when we select the fires larger than 2000–10000 ha in size for the forested areas. Other cases point to the lack of a linear relation between the fire area and the values of all indices, because the fire spread depends on many natural and anthropogenic factors.  相似文献   

4.
The characteristic features of airspace hyperspectral remote sensing (RS) are considered in order to develop classification techniques for relevant images. Currently available approaches to constructing classifiers (computational procedures) are described for recognizing natural and anthropogenic objects in hyperspectral images. We confirm that the methods under development are effective enough with the reduced dimensionality of the feature space of original spectra and the decreased sample volumes in supervising procedures for the selected object classes. Data from joint hyperspectral and aerial photography provide examples of the spectral distributions smoke of different intensities from forest and peat fires in the presence and absence of fire sources, for the smoke coverage of water surfaces, and for the forest vegetation without ignition sources within a selected area. The results obtained in the supervising procedures are used for pattern recognition and scene analysis in airborne images obtained for the test areas during forest-fire season.  相似文献   

5.
The results of 2-year (2010–2012) measurements of the concentrations of organic carbon (OC) and elemental carbon (EC), which were taken at the Zotino Tall Tower Observatory (ZOTTO) Siberian background station (61° N, 89° E), are given. Despite the fact that this station is located far from populated areas and industrial zones, the concentrations of OC and EC in the atmosphere over boreal forests in central Siberia significantly exceed their background values. In winter and fall, high concentrations of atmospheric carbonaceous aerosol particles are caused by the long-range transport (~1000 km) of air masses that accumulate pollutants from large cities located in both southern and southwestern regions of Siberia. In spring and summer, the pollution level is also high due to regional forest fires and agricultural burning in the steppe zone of western Siberia in the Russian–Kazakh border region. Background concentrations of carbonaceous aerosol particles were observed within relatively short time intervals whose total duration was no more than 20% of the entire observation period. In summer, variations in the background concentrations of OC closely correlated with air temperature, which implies that the biogenic sources of organic-particle formation are dominating.  相似文献   

6.
A hydrodynamic model is used to reproduce the atmospheric circulation during forest fires. The dynamics is simulated with an improved model of free convection with allowance for heat flux emission from the fire area. Against the background of the atmospheric circulation patterns obtained, the problem of aerosol evolution and size distribution due to the forest’s combustible materials from the fire area was solved. The evolution of soot particles is described by solving the kinetic equations of condensation and coagulation. The results of numerical experiments to develop a process that considers water-vapor condensation in a moist atmosphere are presented.  相似文献   

7.
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   

8.
Results of spectroscopic measurements of the carbon dioxide total column amount near St. Petersburg during forest fires in the period from August to September 2002 are analyzed. The HYSPLIT model is used to calculate air-mass trajectories and CO distribution on a mesoscale in this period. The HYSPLIT model simulations and measurements of carbon dioxide total column amount yield an estimate of the specific intensity of CO emission in a Pskov forest fire on August 28–September 8, 2002, equal to 0.17–0.26 kg m2. This estimate can be used for an estimation of the integral CO emission from fires in northwestern Russian forests and for model simulations of atmospheric CO concentration fields. The estimate of the CO emission from forest fires that is obtained from ground-based measurements can also be made on the basis of satellite measurements if they contain information on CO in the lower tropospheric layers (0 to 2 km).  相似文献   

9.
A module for simulating of natural fires (NFs) in the climate model of the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM), is extended with respect to the influence of lightning activity and population density on the ignition frequency and fire suppression. The IAP RAS CM is used to perform numerical experiments in accordance with the conditions of the project that intercompares climate models, CMIP5 (Coupled Models Intercomparison Project, phase 5). The frequency of lightning flashes was assigned in accordance with the LIS/OTD satellite data. In the calculations performed, anthropogenic ignitions play an important role in NF occurrences, except for regions at subpolar latitudes and, to a lesser degree, tropical and subtropical regions. Taking into account the dependence of fire frequency on lightning activity and population density intensifies the influence of characteristics of natural fires on the climate changes in tropics and subtropics as compared to the version of the IAP RAS CM that does not take the influence of ignition sources on the large-scale characteristics of NFs into consideration.  相似文献   

10.
The results of the 1995–2008 observations of the concentrations of ozone and nitric oxides in the surface air over the Trans-Siberian Railway using a mobile laboratory (the TROICA experiments) are analyzed. The features of the spatial distribution and time variability of these gases over the continent within the latitudinal belt 48°–58° N are revealed individually for polluted and background conditions. The characteristic features of their distribution are a decrease in the concentration of nitric oxides and an increase in the concentration of ozone in an eastward direction. On the whole, the process of photochemical ozone formation over the territory of Siberia is slow. Noticeable increases in the concentration of ozone are associated with both forest and steppe fires and with the transboundary transport of pollution from the countries of eastern Asia. The dry precipitation of trace gases plays a significantly larger role in Siberia than in coastal and high-altitude unpolluted regions due to powerful and long temperature inversions.  相似文献   

11.
Although the Yellow River Delta and Bohai Sea coastal zone are long distance and different environment with Po River Delta and Adriatic Sea coastal zone, the comparison of data of two different areas and the evolution trend of two areas are quite similar. The influence of natural climatic changes on the evolution of the deltas and coastal zones exists both in ancient and modern times. The cold/wet period occurred in 1300—1400A. D. and 1550 —1850 A.D. within this"large scale" climatie cycle, and shorter periods (10— 35 years) of cold rainy weather alternated with warm/dry period are known as "Bruckner cycles" which have influence on the evolution of the deltas and coastal zones.  相似文献   

12.
A technique for the estimation of changes in components of the water and carbon budgets of coniferous ecosystems as a result of possible anthropogenic climate changes has been developed. The technique is based on the SWAP model of heat, water, and carbon exchanges in coniferous ecosystems, which was previously developed by the authors, and the MAGICC/SCENGEN generator of climatic scenarios for various regions of the Earth. The technique is used for estimating changes in the evapotranspiration and carbon budget of the developing coniferous forest ecosystem in the Loobos experimental site (the Netherlands) in the 21st century in connection with an increase in the anthropogenic emission of greenhouse gases into the atmosphere expected in accordance with the IPCC IS92a scenario of the economic, technological, political, and demographic development of human civilization up to 2100.  相似文献   

13.
ＤｉｖｉｓｉｏｎｏｆｈｙｄｒｏｃｌｉｍａｔｉｃａｒｅａｏｖｅｒＣｈｉｎａｓｅａｓ—Ⅱ．ＣｌｕｓｔｅｒａｎａｌｙｓｉｓａｎｄｆｕｚｚｙＩＳＯＤＡＴＡ．￥ＣｈｅｎＳｈａｎｇｊｉａｎｄＹａｏＳｈｉｙｕ（ＲｅｃｅｉｖｅｄＡｕｇｕｓｔ１，１９９３；ａｃｃｅｐｔ...  相似文献   

14.
Izvestiya, Atmospheric and Oceanic Physics - Results are presented from assessing forest ecosystem disturbances in the forest–steppe zone of Russia’s Central Chernozem region in the...  相似文献   

15.
The authors present a method for obtaining parameters for Sea Beam swath bathymetry which describe the characteristics of abyssal-hill topography. The basic quantity used in the analysis is the distribution of topographic slopes in a region. A convenient means for parameterizing these slopes is through unit vectors that are normal to small patches of the seafloor; the normal vectors are decomposed into azimuthal and dip components. It is found that the azimuthal distribution of the vectors provides a first-order indication of the dominant elongation directions in the topography, including multiple lineations when they are present. It is shown that the slope statistics are relatively independent of long-wavelength depth variations and are robust even if large anomalous features such as seamounts and fracture zones are included in the section of bathymetry analyzed  相似文献   

16.
末次冰期以来冲绳海槽北部古气候变化的孢粉记录   总被引：2，自引：0，他引：2  
通过分析冲绳海槽北部CSH1柱状样的孢粉组合,重建了海槽区邻近岛屿末次冰期以来的植被和气候变化史.将所测岩心的孢粉记录从下到上分为三期:Ⅰ期为热带山地针叶林的繁盛期,松属及亚热带高山的常绿针叶林含量较高,气候干燥温暖;Ⅱ期为旱生草本植物繁盛期,蒿属大量出现,气候干冷;Ⅲ期为常绿阔叶、落叶阔叶林及蕨类植物繁盛期,常绿阔叶及落叶阔叶林成分增加,蕨类孢子达到极高值,草本植物含量剧减,气候温暖潮湿.将一些主要科属花粉的百分含量曲线与格陵兰冰心GISP2δ18O曲线进行了对比分析,发现各花粉百分含量曲线分别在距今4.1~4.6,11.7~13.0,15.4,23.2,29.4,47.4ka显示出了一系列明显的次级波动,这些次级波动与格陵兰冰心δ18O曲线所记录的4ka左右的降温事件、新仙女木(Younger Dryas)事件和Heinrich事件H1,H2,H3和H5在时代上相吻合.尽管格陵兰及北大西洋地区的气候变化影响冲绳海槽地区的途径和载体尚不清楚,但北半球高纬度的气候变化所引发的东亚季风强度在数百年或千年尺度的波动可能是其主要的机制.  相似文献   

17.
殷丽婷  郑伟  高猛  路景钫 《海洋学报》2020,42(6):110-118
利用ArcGIS10.2、ENVI5.1、SPSS26等软件,本文基于经典CASA模型估算了2005年、2010年、2017年庙岛群岛北五岛的净初级生产力(Net Primary Productivity, NPP),从季节、岛屿、景观类型、地形梯度等多种角度分析了NPP的时空分布异质性;进而分析了2005年、2010年、2017年北五岛的景观格局时空分布异质性;探讨了NPP与景观格局时空变化之间的关系及其原因。结果表明:庙岛群岛北五岛平均全年NPP总量为7 520.54 t/a(以碳计),平均密度为406.07 g/(m2·a) (以碳计);NPP分布呈明显的时空分异性;各景观类型平均面积由大到小依次为:针叶林、阔叶林、建设用地、草地、耕地;其NPP平均密度由大到小依次为:阔叶林、针叶林、耕地、草地、建设用地;各景观NPP平均密度随坡度和高差的增大先上升后出现平缓下降态势;坡向对林地NPP影响较大,半阴坡林地NPP平均密度最大;不同地形梯度的NPP年平均密度随时间推移总体呈下降态势;NPP高值出现在山林区域,低值主要在建设用地区域;由于自然地理条件、植物自身生长条件和人类活动强度等原因,NPP时空异质性分布受季节差异、景观格局时空异质性和地形因子影响显著。  相似文献   

18.
The article presents the results of biogeographic zoning of the epi- and mesopelagic region based on nekton areas using a new modification of the Shorygin method. It is shown that the position and boundaries of biogeographic areas are related to real relatively stable elements of the biotope (water masses, currents, frontal zones, eddies, and rings). A pronounced latitudinal pattern of the areas of natural zones is not always seen. Zoning becomes less detailed from the top layer of the epipelagic to mesopelagic region, and the zonalities of mesopelagic and epipelagic areas are not similar. We propose a new zoning approach to solve dynamic biogeography problems.  相似文献   

19.
The results of studying the regions of hail-cell formation in the North Caucasus are considered. The optimal range of the underlying surface heights for their generation is determined based on an analysis of 392 hail cells. It is shown that the majority of hail cells are formed in the zone where the heights of the underlying surface vary from 900 to 2400 m. The most favorable conditions for the formation of hail clouds are recorded in the northern slopes of the Skalistyi (Rocky) ridge. This region accumulates the main maxima of the frequency of first radar echo recording. The second group of the frequency maxima is located over the Pastbishchnyi (Pasturable) and the Lesistyi (Woody) ridges. The generalized scheme for the region under study is constructed of three zones of generation of the first radar echo of the hail cells. It is shown that approximately 70% of hail clouds are formed over submontane and mountainous regions in the central North Caucasus (zones 2 and 3). The directions of motion of hail cells are quantified for each identified zone.  相似文献   

20.
Increase in saturation in natural clayey slopes along coastal zones as a result of tsunamis or storm surges may cause flow slides or failures. One of the common treatments is to increase the overall stability by soil replacement and/or re-compaction, which is often difficult to implement, expensive, and, most importantly, damages the natural vegetation. In this paper, remedial effectiveness of a relatively economical and environmentally friendly method involving insertion of geotextile strips with drainage capability into natural clayey slopes is evaluated through a series of centrifuge tests. The test results demonstrate the effectiveness of the employed technique to increase the stability of slopes and their drainage capability as well as to reduce the deformations under surcharge loadings.  相似文献   

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