Interplanetary Coronal Mass Ejections Resulting from Earth-Directed CMEs Using SOHO and ACE Combined Data During Solar Cycle 23

In this work a total of 266 interplanetary coronal mass ejections observed by the Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph (SOHO/LASCO) and then studied by in situ observations from Advanced Composition Explorer (ACE) spacecraft, are presented in a new catalog for the time interval 1996?–?2009 covering Solar Cycle 23. Specifically, we determine the characteristics of the CME which is responsible for the upcoming ICME and the associated solar flare, the initial/background solar wind plasma and magnetic field conditions before the arrival of the CME, the conditions in the sheath of the ICME, the main part of the ICME, the geomagnetic conditions of the ICME’s impact at Earth and finally we remark on the visual examination for each event. Interesting results revealed from this study include the high correlation coefficient values of the magnetic field \(B_{z}\) component against the Ap index (\(r = 0.84\)), as well as against the Dst index (\(r = 0.80\)) and of the effective acceleration against the CME linear speed (\(r = 0.98\)). We also identify a north–south asymmetry for X-class solar flares and an east–west asymmetry for CMEs associated with strong solar flares (magnitude ≥ M1.0) which finally triggered intense geomagnetic storms (with \(\mathrm{Ap} \geq179\)). The majority of the geomagnetic storms are determined to be due to the ICME main part and not to the extreme conditions which dominate inside the sheath. For the intense geomagnetic storms the maximum value of the Ap index is observed almost 4 hours before the minimum Dst index. The amount of information makes this new catalog the most comprehensive ICME catalog for Solar Cycle 23.     

Study of water renewal and sedimentation of a square harbor encapsulated in a coastal front with seawalls due to wind-induced hydrodynamic circulation

In the current study in the middle of a coastal zone,a harbor basin in the form of a square area recessed to the front is considered.A breakwater of variable length and position offers protection from waves.The water renewal time and the self-purification capacity of the harbor under the influence of alongshore currents due to wind-induced water circulation of varying intensities were examined.Furthermore,the transport of particulate matter released from the upstream side of the coastal zone and the possible influence(via sedimentation)on the lateral basin was investigated.The current study was based on the use of a two-dimensional depth-averaged hydrodynamic model and a quasi-three-,dimensional transport model while the effect of partial closing of the harbor's entrance was examined.The(1)adjustment and(2)validation of the reliability of the numerical model at a laboratory level were done using a recent research based on the use of a particle image velocimetry(PIV)measurements ensuring very good agreement between numerical and experimental results.The current study showed that the partial closing of the opening between the harbor basin and the extended coastal zone,with a breakwater of length equal to 1/3 of the opening,seems to be the most acceptable technical solution.     

美国犹他州中部Green River流域农业区硒的淋出速度和形态

尽管硒(Se)是一种重要的生命元素,但是即使浓度很低,也有可能会造成危害。在美国西部,包括犹他州中部GreenRiver流域斯图尔特湖水鸟管理区,大面积的农业排水区中都存在硒。为了对该场地进行地球化学研究和进行修复,取未受扰动的岩芯分析了硒的形态、浓度和迁移。用酸消解进行前处理对土壤和曼柯斯页岩风化壳进行了分析,结果表明,硒的最高浓度为3ppm,采用连续萃取法的分析结果表明,有19%~79%的硒是以有机物形式存在的,有17%~67%的硒是以元素形式存在的。柱实验研究结果表明,硒可以从深部土壤迅速淋出,可溶性硒的质量分数很高,达到了292×10-9。表层土壤中硒的淋出速度最初很慢,但是非常稳定,最终淋出速度会超过深部土壤。当对岩心通过放射灭菌后,表层土壤和深部土壤的淋出速度都会加快。计算结果表明,在修复富含硒的土壤时,所需的水量很大,每kg土壤需要约500L的水量。     

Filling in missing sea-surface temperature satellite data over the Eastern Mediterranean Sea using the DINEOF algorithm

The Data Interpolating Empirical Orthogonal Functions method is a special technique based on Empirical Orthogonal Functions and developed to reconstruct missing data from satellite images, which is especially useful for filling in missing data from geophysical fields. Successful experiments in the Western Mediterranean encouraged extension of the application eastwards using a similar experimental implementation. The present study summarizes the experimental work done, the implementation of the method and its ability to reconstruct the sea-surface temperature fields over the Eastern Mediterranean basin, and specifically in the Levantine Sea. L3 type Satellite Sea-surface Temperature data has been used and reprocessed in order to recover missing information from cloudy images. Data reconstruction with this method proved to be extremely effective, even when using a relatively small number of time steps, and markedly accelerated the procedure. A detailed comparison with the two oceanographic models proves the accuracy of the method and the validity of the reconstructed fields.     

An integrated GIS-based method for wind-power estimation: application to western Cyprus

This study presents an integrated method for the estimation and analysis of potential wind-energy resources in Cyprus, which is applied at selected sites on the western side of the island. Firstly, a statistical analysis of wind speed and direction data was conducted at six meteorological stations in western Cyprus, establishing daily, monthly and annual variations of wind speed. Also examined were the Weibull distributions of the wind at each site. These wind statistics serve as the basis for estimating corrected statistical distributions over the extended study areas, which were calculated using the Wind Atlas Analysis and Application Program (WAsP) that modifies wind flow estimates based on local topographic effects. As a result, a geographic and wind-resource database was formulated around each station. Aggregation of this data using statistical weighting methods allows the extrapolation of observed results and the visualization for selected hours of the day over the western part of Cyprus. The results indicate the strong influence of the sea-breeze on the island’s wind potential, and identify a number of areas of higher wind-energy potential suitable for wind-resource exploitation. It is hoped that both the methodology applied and results obtained can be further used by potential investors and wind-energy developers.     

Multivariate statistics and hydrogeochemical modeling for source identification of major elements and heavy metals in the groundwater of Qareh-Ziaeddin plain,NW Iran

The present study aims to evaluate the possible source of major and some minor elements and heavy metals in the groundwater of Qareh-Ziaeddin plain, NW Iran with respect to chemical elements, saturation index, and multivariate statistics including correlation coefficient, cluster analysis, and factor analysis. Groundwater samples were collected in Jun 2016 and measured with respect to EC, pH, major and some minor elements and heavy metals including Fe, Mn, Zn, Cr, Pb, Cd, Al, and As. Among all the measured parameters, some of the samples exceed the World Health Organization (WHO) guideline value for EC, Na, Mg, HCO₃, SO₄, Cl, NO₃, F, As, Zn, and Pb. The results of correlation analysis show that weathering and dissolution of minerals especially evaporites and silicates, water-rock interaction, and cation exchange are dominant occurred processes in the groundwater of the study area. Also, denitrification process is occurred in the groundwater system. Cluster analysis categorizes the samples into three distinct groups which are different based on their EC and dependent variables, e.g., Na, Ca, Cl, SO₄ and pH, Pb, Cd, and As. It can be found that volcanic, evaporite, and clay formations have the least impact on the chemistry of the cluster 1 samples while clay and evaporite formations have the highest impact on the cluster 3 and also calcareous formations on cluster 2. Factor analysis shows that five factors, with total variance of 83%, are effective in the release of heavy metals and groundwater chemistry which are mostly geogenic.     

Assessment of global wave models on regular and unstructured grids using the Unresolved Obstacles Source Term

Ocean Dynamics - The Unresolved Obstacles Source Term (UOST) is a general methodology for parameterizing the dissipative effects of subscale islands, cliffs, and other unresolved features in ocean...     

Slug test in confined aquifers, the over-damped case: quasi-steady flow analysis

In the great majority of slug tests performed in wells fully penetrating confined geologic formations, and for over-damped conditions, the response data are evaluated with the transient-flow model of Cooper et al. (1967) when the radial hydraulic conductivity K(r) and the coefficient of specific storage S(s) are to be estimated. That particular analytical solution, however, is computationally involved and awkward to use. Thus, groundwater professionals often use a few pre-prepared type-curves to fit the data by a rough matching procedure, visually or computationally. On the other hand, the method of Hvorslev (1951), which assumes the flow to be quasi-steady, is much simpler but yields only K(r) estimates. In this work, we develop a complete quasi-steady flow model that includes a storage balance inside the aquifer and allows estimating K(r) and S(s) simultaneously, through matching of the well response data to a type-curve. The new model approximates the model of Cooper et al. closely and has the practical advantage that its solution type-curves are generated easily using an electronic spreadsheet, so that the optimal fit of data by a type-curve can be readily automated.     

The problem of depth in geology: When pressure does not translate into depth

We review published evidence that rocks can develop, sustain and record significant pressure deviations from lithostatic values. Spectroscopic studies at room pressure and temperature (P-T) reveal that in situ pressure variations in minerals can reach GPa levels. Rise of confined pressure leads to higher amplitude of these variations documented by the preservation of α-quartz incipiently amorphized under pressure (IAUP quartz), which requires over 12 GPa pressure variations at the grain scale. Formation of coesite in rock-deformation experiments at lower than expected confined pressures confirmed the presence of GPa-level pressure variations at elevated temperatures and pressures within deforming and reacting multi-mineral and polycrystalline rock samples. Whiteschists containing garnet porphyroblasts formed during prograde metamorphism that host quartz inclusions in their cores and coesite inclusions in their rims imply preservation of large differences in pressure at elevated pressure and temperature. Formation and preservation of coherent cryptoperthite exsolution lamellae in natural alkali feldspar provides direct evidence for grain-scale, GPa-level stress variations at 680°C at geologic time scales from peak to ambient P-T conditions. Similarly, but in a more indirect way, the universally accepted’ pressure-vessel’ model to explain preservation of coesite, diamond and other ultra-high-pressure indicators requires GPa-level pressure differences between the inclusion and the host during decompression at temperatures sufficiently high for these minerals to transform into their lower pressure polymorphs even at laboratory time scales. A variety of mechanisms can explain the formation and preservation of pressure variations at various length scales. These mechanisms may double the pressure value compared to the lithostatic in compressional settings, and pressures up to two times the lithostatic value were estimated under special mechanical conditions. We conclude, based on these considerations, that geodynamic scenarios involving very deep subduction processes with subsequent very rapid exhumation from a great depth must be viewed with due caution when one seeks to explain the presence of microscopic ultrahigh-pressure mineralogical indicators in rocks. Non-lithostatic interpretation of high-pressure indicators may potentially resolve long-lasting geological conundrums.