Spatial analysis of monthly precipitation in Turkey   总被引：2，自引：1，他引：1  

Z. Şen  Z. Habib 《Theoretical and Applied Climatology》2000,67(1-2):81-96

Summary  The principal objectives of this paper are to develop and validate an optimum interpolation method for the spatial analysis of monthly precipitation in Turkey. A two-dimensional optimum interpolation objective analysis scheme has been developed for the spatial analysis of precipitation. The model is developed for generating statistically optimum interpolation based on the irregular distribution of meteorological stations. One question that affects the optimum interpolation method and, indeed, all such techniques, is how many observations should be allowed to influence a given grid point? The method developed in this paper addresses this question. For the implementation of the method, 52 stations are considered for Turkey, with 30 years of monthly data at each point. It is observed that each monthly average spatial correlation function shows a monotonically decreasing pattern based on 15 km interval averages. The method provides high estimation accuracy in dense station locations such as in northwestern Turkey. Precipitation contour maps obtained by the optimum interpolation method indicate two spatial trends over Turkey which have not been identified in any previous study. Received June 24, 1999/Revised April 26, 2000  相似文献   

Search for neutrino decay during the 1999 solar eclipse     

S. Cecchini  G. Giacomelli  D. Haşegan  G. Mandrioli  O. Mariş  L. Patrizii  A. Plaian  V. Popa  L. Ştefanov  V. Văleanu 《Astrophysics and Space Science》2000,273(1-4):35-41

The solar neutrino problem could arise from oscillation of one neutrinotype into a secondtype. Neutrinos would have a mass and there could be the possibility ofradiative neutrino decays. We discuss the search for neutrino decaysduring the 1999 solar eclipse: it involves the emitted visible photons,while neutrinos travel from the Moon to the Earth. The concept and themain characteristics of the NOTTE experiment are presented.  相似文献   

Seasonal variation of carbon dioxide fluxes over irrigated soybean (Glycine max L.)     

Levent Şaylan  Reiji Kimura  Erdenebayar Munkhtsetseg  Makio Kamichika 《Theoretical and Applied Climatology》2011,105(1-2):277-286

In this study, variations in carbon dioxide (CO₂) fluxes resulting from gross primary production (GPP), net ecosystem exchange (NEE), and respiration (R _e) of soybean (Glycine max L.) were investigated by the Eddy Covariance method during the growing period from June to November 2005 on an irrigated sand field at the Arid Land Research Center, Tottori University in Tottori, Japan. Although climatic conditions were humid and temperate, the soybeans required frequent irrigation because of the low water holding capacity of the sandy soil at the field site. Finally, it has been found that the accumulated NEE, GPP, and R _e fluxes of soybean over 126 days amount to ?93, 319, and 226 gC m^?2, respectively. Furthermore, the average ratio of GPP to R _e was 1.4 and the average ratio of NEE to GPP was about ?0.29 for the growth period of soybean. Daily maximum NEE of ?3.8 gC m^?2 occurred when LAI was 1.1.  相似文献   

Geochemical evidence of the renewal of volcanic activity inferred from CO<Subscript>2</Subscript> soil and SO<Subscript>2</Subscript> plume fluxes: the 2007 Stromboli eruption (Italy)     

Salvatore Inguaggiato  Fabio Vita  Dmitri Rouwet  Nicole Bobrowski  Sabina Morici  Aldo Sollami 《Bulletin of Volcanology》2011,73(4):443-456

On 27 February 2007, a new eruption occurred on Stromboli which lasted until 2 April. It was characterized by effusive activity on the Sciara del Fuoco and by a paroxysmal event (15 March). This crisis represented an opportunity for us to refine the model that had been developed previously (2002–2003 eruption) and to improve our understanding of the relationship between the magmatic dynamics of the volcano and the geochemical variations in the fluids. In particular, the evaluation of the dynamic equilibrium between the volatiles (CO₂ and SO₂) released from the magma and the corresponding fluids discharged from the summit area allowed us to evaluate the level of criticality of the volcanic activity. One of the major accomplishments of this study is a 4-year database of summit soil CO₂ flux on the basis of which we define the thresholds (low–medium–high) for this parameter that are empirically based on the natural volcanological evolution of Stromboli. The SO₂ fluxes of the degassing plume and the CO₂ fluxes emitted from the soil at Pizzo Sopra la Fossa are also presented. It is noteworthy that geochemical signals of volcanic unrest have been clearly identified before, during and after the effusive activity. These signals were found almost simultaneously in the degassing plume (SO₂ flux) and in soil degassing (CO₂ flux) at the summit, although the two degassing processes are shown to be clearly different. The interpretation of the results will be useful for future volcanic surveillance at Stromboli.  相似文献   

Comparison of the attenuation properties for two different areas in eastern Anatolia,Turkey     

Ufuk Aydin  Şakir Şahin 《Soil Dynamics and Earthquake Engineering》2011

In this study, the attenuation properties of the crust and the quality factor of S wave in eastern Anatolia (Turkey) were determined by local earthquakes for two different areas, Oltu and Erzurum. Seismic wave attenuation can be changed with high pressure or structural effects. Therefore, we argued that the estimation of attenuation coefficient in seismic active zones in Eastern Anatolia is a very useful tool to determine seismic activities. It uses regional waveform data set from two stations, OLT and ERZ, for 95 events that occurred in these regions between 2001 and 2005. The attenuation has been determined using the Chobra–Alexeev model based on the epicenter distance–amplitude relations. This model allows for investigation of the effects of variations in attenuation properties for different areas. We introduced a new magnitude formula for these areas using the amplitude normalization methods for reference values M_L=4, so as to correct effects of the magnitudes. We also determined velocity of seismic waves. The average attenuation coefficient (α), average quality factor (Q_s) and P and S waves velocities were obtained with normalized amplitude values for Erzurum (ERZ) and Oltu (OLT) as 0.0135 km⁻¹, 37, 6.20 km/s and 3.38 km/s and 0.0151, 34, 6.13 and 3.48.  相似文献   

Theoretical derivation of precipitation coverage probability from a set of heterogeneous point probabilities     

Zekai Şen 《Theoretical and Applied Climatology》2013,114(3-4):575-581

Various meteorological studies require probabilistic modeling such as the flood, drought, and wet and dry spell occurrences. The most commonly employed approaches are based on the binomial probability distribution function (pdf), which is valid for homogeneous temporal and spatial probabilities. However, in practice, heterogeneous probabilities are very common, and in this case, the classical binomial pdf cannot be employed. This paper presents a rigorous probabilistic methodology for heterogeneous probabilities by considerations from the random field concept. The general form of the binomial pdf is derived and it is shown that for homogeneous probabilities it yields the classical binomial pdf exactly. The necessary analytical formulations are derived with the assumption that the meteorological occurrences at a set of sites or time periods (day, month, and year) are independent from each other. The probability statements derived in this paper are helpful in predicting the regional and temporal probable potential future meteorological occurrences. The application of the proposed methodology is presented for annual precipitation occurrences at six meteorology stations around Istanbul, Turkey.  相似文献   

Radiative transfer in disc galaxies – III. The observed kinematics of dusty disc galaxies     

Maarten Baes †  Jonathan I. Davies  Herwig Dejonghe  Sabina Sabatini  Sarah Roberts  Rhodri Evans  Suzanne M. Linder  Rodney M. Smith  W. J. G. de Blok 《Monthly notices of the Royal Astronomical Society》2003,343(4):1081-1094

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A Multi-Angle Averaging Theorem Applied to the J2 Problem     

Cătălin Cucu-Dumitrescu  Dan Şelaru 《Celestial Mechanics and Dynamical Astronomy》1997,69(3):255-270

A particular multi-angle averaging theorem for systems admitting a finite Fourier expansion of the field is presented, together with its application to the problem of motion around an oblate planet (the J₂ problem), in harmonic oscillator formulation. This method of approximate integration has the advantage of working with (close on) directly measurable elements. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Utilization of waste marble to enhance volume change and strength characteristics of sand-stabilized expansive soil     

Şerife Öncü  Huriye Bilsel 《Environmental Earth Sciences》2018,77(12):461

In this paper, marble waste is evaluated as a secondary material to be utilized as potential stabilizer to improve the volume change and strength characteristics of sand-amended expansive soil, proposed as a possible landfill, pavement or sub-base material in a semi-arid climate. An experimental program was conducted on sand-expansive soil enhanced with marble waste, abundantly found as a by-product of construction industry, obtained from two different sources with different gradations, denoted as marble powder (MP) and marble dust (MD). One-dimensional swell, volumetric shrinkage, consolidation, unconfined compressive and flexural strength tests were conducted on expansive soil–sand mixtures with 5, 10 and 20% waste marble inclusions over curing periods of 7, 28 and 90 days. Test results showed that 10% marble powder and 5% marble dust by dry mass were the optimum amounts for mitigating the swell–shrink potential and compression index as well as yielding the highest unconfined compressive and flexural strength values. Moreover, the rate of reduction in swell potential versus the flexural strength over the curing periods studied is highest in 10% MP- and 5% MD-included specimens, the latter being more insensitive to this change. The soil mixtures displayed brittle behavior after marble addition, hence its utilization as a secondary additive to sand-amended expansive soil is recommended for soils exposed to lower flexural loads such as light traffic.  相似文献   

The effect of pumice as aggregate on the mechanical and thermal properties of foam concrete     

Şemsettin Kilincarslan  Metin Davraz  Mehmet Akça 《Arabian Journal of Geosciences》2018,11(11):289

Pumice is a porous rock, which is formed as a result of volcanic activity and does not include any crystal water. Its porous structure makes it lightweight and provides advantage for heat and sound isolation. Foam concrete is a type of lightweight concrete. Foam concrete is obtained by adding the foam obtained from the agent to the mixture of cement, water, and aggregate. Foam concrete is an environmentally friendly structure and insulation material which provides light, heat, and impact sound insulation that can be used in place of the building elements used in the interior-exterior walls and floors of all buildings. Because of the lack of coarse aggregate in the foam concrete mix, it has some structural problems and this limits its usage area. In this study, four different types of pumice aggregates and stone powder were used to overcome the structural problems of foam. The cement dosages (250 kg/m³), aggregate amounts (250 kg/m³), fresh concrete densities and w/c ratio (0.45) were kept constant in all foamed concrete mixtures. Then, physical, mechanical, and thermal conductivity properties of the resulting foam concretes were investigated. When the findings were evaluated, the most suitable type of lightweight aggregates for use in foam concrete have been determined in terms of compressive strength and thermal conductivity properties. In all aggregate groups, Nevsehir Pumice has the highest compressive strength while Karaman Pumice has the lowest thermal conductivity. However, when both properties were evaluated together, it was determined that the most favorable lightweight aggregate was Nevsehir Pumice.  相似文献