Statistical Characteristics of Meteoroid Parameters in the Earth’s Atmosphere     

L. F. Chernogor 《Kinematics and Physics of Celestial Bodies》2018,34(3):134-146

Statistical characteristics of meteoroids with kinetic energy from 0.1 to 440 kt TNT are estimated based on NASA satellite observations made in 1994–2016. The distributions of the number of falling meteoroids are constructed and analyzed based on the values of their initial kinetic energy, initial velocity, initial mass, altitude, geographic coordinates of the maximum total radiated energy region, and the year of the fall. Correlation dependences “mass–initial kinetic energy,” “maximum total radiated energy region altitude–initial kinetic energy,” and “maximum total radiated energy region altitude–initial velocity (the square of the initial velocity)” are constructed.  相似文献   

Revised recommended methods for analyzing crater size-frequency distributions          下载免费PDF全文

Stuart J. Robbins  Jamie D. Riggs  Brian P. Weaver  Edward B. Bierhaus  Clark R. Chapman  Michelle R. Kirchoff  Kelsi N. Singer  Lisa R. Gaddis 《Meteoritics & planetary science》2018,53(4):891-931

Impact crater populations help us to understand solar system dynamics, planetary surface histories, and surface modification processes. A single previous effort to standardize how crater data are displayed in graphs, tables, and archives was in a 1978 NASA report by the Crater Analysis Techniques Working Group, published in 1979 in Icarus. The report had a significant lasting effect, but later decades brought major advances in statistical and computer sciences while the crater field has remained fairly stagnant. In this new work, we revisit the fundamental techniques for displaying and analyzing crater population data and demonstrate better statistical methods that can be used. Specifically, we address (1) how crater size-frequency distributions (SFDs) are constructed, (2) how error bars are assigned to SFDs, and (3) how SFDs are fit to power-laws and other models. We show how the new methods yield results similar to those of previous techniques in that the SFDs have familiar shapes but better account for multiple sources of uncertainty. We also recommend graphic, display, and archiving methods that reflect computers’ capabilities and fulfill NASA's current requirements for Data Management Plans.  相似文献   

Differentiated payments for environmental services schemes: Amethodology proposal     

Carlos R.AGUILAR-GóMEZ  Sergio FRANCO-MAASS  Tizbe T.ARTEAGA-REYES 《山地科学学报》2018,15(8):1693-1710

Payment schemes for environmental services face serious budget constraints in Mexico. Payments are equally distributed among forest owners, and the governmental agencies that make payments to beneficiaries do not evaluate the amount of environmental services produced by forested areas. This lack of evaluation could lead to economic and environmental deficiencies that restrict the possible benefits of such programmes. In general, these programmes do not achieve their conservation objectives, and local beneficiaries are not involved in the design or application of these programmes. Similarly, the Payments for Hydrological Environmental Services (PHES) programme of the State of Mexico, Mexico, makes equal payments to beneficiaries of forested areas considering tree density. The objective of the present work was to create a methodology for determining differentiated payments schemes for hydrological environmental services, prioritising areas that contribute the most to groundwater recharge and promote the participation of society. In the Nevado de Toluca Natural Protected Area, the environmental criteria of forest type, tree density and aquifer overexploitation as well as social participation were considered in a multi-criteria analysis implemented in a Geographic Information System. A methodology was developed to determine differentiated payments based on specific forest characteristics that influence the potential capacity of forests to recharge groundwater reserves in addition to the level of social participation. In particular, social participation is key as it could ensure the viability of PHES programmes as conservation alternatives in forested areas with high groundwater recharge potential.  相似文献   

Irregular Phenomena in Magnetically Conjugate Regions of the <Emphasis Type="Italic">F</Emphasis>2 Layer of the Ionosphere     

N. P. Sergeenko 《Geomagnetism and Aeronomy》2018,58(6):823-830

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Planetary Wave Periods in <Emphasis Type="Italic">foF</Emphasis>2 Time Variations Based on Winter Data from Kaliningrad Station in 2008−2010     

Yu. N. Koren’kov  F. S. Bessarab  N. A. Koren’kova  V. S. Leshchenko 《Geomagnetism and Aeronomy》2018,58(3):420-429

The study presents the results of the analysis of the F2-layer critical frequency variations obtained for the winter periods of 2008–2010, during which sudden stratospheric warmings were observed. The data were obtained at Kaliningrad ionospheric station (54.6° N, 20° E) with the Parus digital ionosonde in standard sounding mode. The mean daily foF2 values were used in the analysis. The results of spectral analysis based on continuous wavelet transform showed that, during all of the warmings that occurred in 2008–2010, the foF2 time variations demonstrated the presence of wave processes with periods of approximately 5?6 days, as well as more extended processes with periods of ~10?13 and 23?30 days. These periods coincide with the characteristic periods of planetary waves observed in the mesosphere during sudden stratospheric warmings, while the 13- and 30-day periods can be conditioned by the influence of the Sun.  相似文献   

Effect of Bank Deformations on Pollutant Transport in Rivers in Cryolithozone: Laboratory and Mathematical Modeling     

E. I. Debol’skaya  I. I. Gritsuk  V. K. Debol’skii  D. N. Ionov  O. Ya. Maslikova 《Water Resources》2018,45(4):542-552

The study is focused on pollution transport in rivers flowing in cryolithozone and takes into account possible channel deformations caused by thawing of permafrost rocks in which the channel runs. The methods used are laboratory and mathematical modeling. The mathematical model consists of four blocks: hydrodynamic, thermal, deformation, and pollutant transport. The model was validated and tested against the data of a laboratory experiment. Numerical experiments suggested conclusions regarding the propagation of pollutants entering the flow from sources in thawing bank slopes and on river floodplain.  相似文献   

The Present-Day Hydrochemical State of Hydroecosystems Suffering the Technogenic Effect of AO Apatit     

M. A. Chukaeva  V. A. Matveeva 《Water Resources》2018,45(6):935-940

Hydrochemical studies have been carried out to assess the extent of molybdenum and aluminum pollution of wastewaters from Apatit plant and natural water bodies suffering higher technogenic load. The main sources of surface water pollution by aluminum and molybdenum have been identified. The interrelationship between the natural and technogenic factors at the formation of aluminum- and molybdenum-containing wastewaters as well as quarry and mine waters has been studied.  相似文献   

The Hydrochemical Evolution of Water in Lake Karymskii during 1996‒2015 after an Underwater Eruption in Kamchatka     

A. G. Nikolaeva  G. A. Karpov  A. Yu. Bychkov 《Journal of Volcanology and Seismology》2018,12(2):109-127

This study considers variations in the physical and chemical characteristics of water in Lake Karymskii for the period from January 1996, when a phreatomagmatic eruption occurred in the lake, until 2015. Our monitoring revealed two characteristic sets of components whose behavior characterizes the hydrochemical evolution of lake water: a comparatively rapid exponential decay of the concentrations of SO₄, Ca, and Mg and a slow decrease in the concentrations of Cl, Na, and K. We arrived at the conclusion that two components of the fluid flow (a fumarolic and a hydrothermal component proper) simultaneously occurred during the eruption and thus had an effect on the lake water. We adduce evidence to show that the water balance and the chemical composition of Lake Karymskii stabilized toward 2015.  相似文献   

Method for Constructing a Model of a Geoelectric Section Taking into Account Seasonal Variations Based on Data from Long-Term Vertical Electric Sounding Monitoring in Search of Earthquake Precursors     

A. V. Desherevskii  I. N. Modin  A. Ya. Sidorin 《Seismic Instruments》2018,54(4):424-436

The study analyzes data from high-precision measurements of the apparent resistivity by a stationary multielectrode vertical electric sounding (VES) system including 12 current and 4 potential lines spaced 2–650 m apart. Observations had been being carried out at the Garm test area on a daily basis for 12 years in an earthquake prediction experiment. The use of special technical methods during measurements ensured an instrumental error of about 0.01%. The virtual error of each individual measurement of apparent resistivity (taking into account all possible noise) was 0.1–0.2%. The availability of more than 3000 VES curves measured in different seasons allows us to propose a new approach to constructing a geoelectric section model. To solve the inverse VES problem, a set of 36 averaged 10-day VES curves was analyzed, each of which was obtained by averaging approximately 100 individual VES curves accumulated in the same 10-day period of the annual (seasonal) cycle in different years. Comparative analysis of these curves made it possible to calculate and include corrections for stationary geological noise in the model. As a result, it was possible to substantially reduce (by an order of magnitude) the discrepancies in fitting the curves and dramatically narrow the equivalence domain. Based on the results of our analysis, we have constructed a model of a four-layer horizontally layered geoelectric section of the Khazor-Chashma depression to adequately describe not only the averaged section, but also its seasonal variations throughout the year. The stability in estimating the model parameters is studied. To further reduce the equivalence domain, we propose that the layer thicknesses be fixed. This model can be used not only to study the aforementioned characteristics of the section, but also to monitor time variations of resistivity in individual layers of the section. This will significantly improve the resolving power of systems for detecting time variations in geoelectric sections, including when searching for earthquake precursors.  相似文献   

Prevention of Shield-Induced Desynchronosis in Invertebrates by a Variable Magnetic Field of Extremely Low Frequency     

N. A. Temuryants  K. N. Tumanyants  A. S. Kostyuk  N. S. Yarmolyuk  E. N. Tumanyants 《Izvestiya Atmospheric and Oceanic Physics》2018,54(7):661-666

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