Fluctuations in some climate parameters

There is argument as to the extent to which there has been an increase over the past few decades in the frequency of the extremes of climatic parameters, such as temperature, storminess, precipitation, etc, an obvious point being that Global Warming might be responsible. Here we report results on those parameters of which we have had experience during the last few years: Global surface temperature, Cloud Cover and the MODIS Liquid Cloud Fraction. In no case we have found indications that fluctuations of these parameters have increased with time.     

Rolling torus structures in astronomy

Ken Barker puts forward an idea that may have a place in astrophysical modelling.
Torus structures that roll and orbit the centre of mass can produce a family of nested, almost elliptical orbits. These orbits, with the centre of mass at one focus, have a range of eccentricities and are inclined to the principal plane of the torus. Individual orbiting particles have an "anti-collision feature" from the nature of the rolling torus. In turn, because the torus can be regarded as a family of nested elliptical orbits, it rolls without needing any additional force. The system is acted upon only by central gravitational attraction and has low dissipation and a long lifetime.     

On the use of wind profilers in meteorology

As an introduction to this special issue of Annales Geophysicae a review is given of the applicability and performance of wind profilers. In meteorology, wind profilers play an increasingly important role. They can provide upper-wind measurements with an accuracy comparable to radiosonde data, but with a significantly higher temporal resolution. Height coverage and vertical resolution depend on the operating frequency, which, depending on the application, is usually chosen to be around 50, 400 or 1000 MHz. Measurements from stand-alone profilers in sparse data areas as well as data from wind profiler networks - which have increased the spatial resolution of an existing radiosonde network - have shown a positive impact on numerical weather forecasting. Information from nearby profilers can help the individual meterologist to optimize local short-term weather forecasts. In atmospheric research, wind profilers have been used for various boundary layer studies. In several mesoscale monitoring experiments wind profilers have played an important role. In Europe the development and implementation of wind profiler networks have been supported since 1987 by the CEC-sponsored COST-74 project. A follow-up project will probably start in 1994. Several topics deserve attention. A further assessment of the quality of wind profiler measurements is important. Automatic quality control procedures should be refined. Improved data assimilation techniques in numerical models will enable a better use of the high temporal resolution of wind profiler data. For a cost-effective development and use of wind profilers, the realization of frequency allocations, as globally harmonized as possible, is essential. Finally, the integration of wind profilers with other complementary measuring techniques is important.     

2003年中国地震救灾评价

2003年，中国地震灾害救援取得巨大成就。中央地震应急资金在震后1～2天拨付到灾区，大大增强了地震救灾的能力；救灾物资走向标准化；建立中央救灾物资储备库；地震紧急救援队开始发挥作用。但在救援物资调度上还有待改进。     

Earthquake swarms and volcanism in New Zealand

The term « swarm » is used to describe a group of related earthquakes, concentrated in space and time, without an obvious principal event. Large shallow earthquakes are often followed by aftershocks, but the pattern in which aftershocks occur differs in detail from that of a swarm. Sequences of New Zealand earthquakes that have been called swarms differ markedly from one another. The most vigorous of them, near Taupo in 1922, appears to have been an ordinary tectonic earthquake accompanied by foreshocks and aftershocks, and by surface faulting. No fault movements accompanied the 1964 swarm in the same area. Other localities that have experienced swarms include Great Barrier Island, Matamata, Kawerau, and Opunake. Swarms are considered by some writers to be characteristic of volcanic regions. Although all New Zealand swarms have occurred in areas of Quaternary volcanism, there are still no observations showing what part, if any, volcanism plays in the generation of earthquake swarms.     

Interaction between the electromagnetic and acoustic fields in the marine environment

The possibility of generation of additional acoustic harmonics in the geomagnetic field after the propagation of an acoustic wave in the conducting medium through the region with a variable magnetic field has been considered. Two possible procedures of such a generation have been analyzed: the parametric procedure and the dynamic procedure related to ponderomotive forces. The expressions have been obtained for three acoustic harmonics generated by an oscillating magnetic field.     

The impact of parameter lumping and geometric simplification in modelling runoff and erosion in the shrublands of southeast Arizona

There have been many studies of hydrologic processes and scale. However, some researchers have found that predictions from hydrologic models may not be improved by attempting to incorporate the understanding of these processes into hydrologic models. This paper quantifies the effect of simplifying watershed geometry and averaging the parameter values on simulations generated using the KINEROS2 model. Furthermore, it examines how these changes in model input effect model output. The model was applied on a small semiarid rangeland watershed in which runoff is generated by the infiltration excess mechanism. The study concludes that averaging input parameter values has little effect on runoff volume and peak in simulating runoff. However, geometric simplification does have an effect on runoff peak and volume, but it is not statistically significant. In contrast, both averaging input parameter values and geometric simplification have an effect on model‐predicted sediment yield. Copyright © 2005 John Wiley & Sons, Ltd.     

A marine kill in New Jersey coastal waters

A kill of lobsters around wrecks off the New Jersey coast seem not to be a direct result of pollution but may have been due to an influx of water causing reduced oxygen levels combined with high temperatures. Mortalities of this kind have been observed before in the area but it is not known if this is an annual event or due to abnormal circumstances. It would be worth keeping the situation under review in the future.     

The state of a river in pechora basin after an oil spill: Assessment of changes in zooplankton community

The long-term dynamics of zooplankton in a northern river has been studied in the context of its pollution after an oil pipeline break. Oil has been shown to have both negative and stimulating effect on planktonic communities and populations, and the role of the drainage area in river system self-purification is studied. Artificial settling water bodies, which had been formed by regulation of polluted flows in the river, have been found to have additional significance as biological regenerators of aquatic ecosystems.     

Interpreting a Pumping Test Influenced by Another Well in an Anisotropic Aquifer

In confined aquifers the influence of neighboring active wells is often neglected when interpreting a pumping test. This can, however, lead to an erroneous interpretation of the pumping test data. This article presents simple methods to evaluate the transmissivity tensor and storativity of an anisotropic confined aquifer when there is an interfering well in the neighborhood of the tested well. Two methods have been developed depending on whether the tested well or the interfering well is the first in operation. These new methods yield better estimates of the hydraulic parameters than when the influence of the interfering well is neglected. These methods have then been used on data obtained from numerical models with an interfering well and the results have been compared to an analytical method that neglects the influence of the interfering well. The methods require knowledge of the pumping rate of the interfering well and the time elapsed since the pumping started in each well. If the interfering well started pumping before the tested well, the method does not require knowledge of the aquifer piezometric level at the beginning of the test, which is often unknown in this case. As for the method without interference, at least three monitoring wells (MWs) are needed, the position of which influences the accuracy of the estimated parameters. Some recommendations concerning MWs position have been given to get more accurate results according to the sought parameter.     

Giant phenocryst basalts in the deccan trap

This paper gives an account of some unusual porphyritic basalts containing very large phenocrysts of plagioclase, averaging from 3 cm to 5 cm in length, and at places as large as 10 to 12 cm in length. These flows have been noticed at more than 20 localities, spread all over Western Maharashtra, occurring between levels of 100 feet below sea level (seen in a drill-core) and an elevation of more than 4000 feet above sea level. They appear to have a considerable lateral extent, some of them having been observed to extend for more than ten miles. In vertical extent, the flows were found to vary from 40 to 150 feet. The giant phenocrysts commonly show cross-twinning. In some flows due to repeated cross-twinning they give star shaped appearance. At places they also occur in clusters. In portions of some flows the tablets seem to have settled at the bottom and are seen in horizontal positions. In hydrothermally altered portions of some flows the phenocrysts are altered and in some patches seem to have been completely destroyed. As a rule, the plagioclase weathers more quickly than the ground mass producing a very characteristic pitted appearance. Some flows seem to have contained large crystals of olivine which have been altered to iddingsite. Highly vesicular and amygdaloidal giant phenocrvst basalts are also met with.     

Some problems of plane strain in a non-homogeneous isotropic cylinder

Summary The expressions for stresses and extension have been obtained in an isotropic circular cylinder in a state of plane strain, the elastic constants and the density of the material varying exponentially and the results have been compared with those in the homogeneous case.     

崇明地震台FGE磁通门磁力仪D分量基线值的确定

基线值是考察记录仪运行是否稳定可靠的一个重要指标。本文以记录仪的D分量为例,通过认真仔细地分析与探索,使用数据处理的方法,解决了崇明台FGE磁通门磁力仪基线值不稳定的问题。这对基线值的确定和日常的数据处理都具有一定的指导意义。     

Solar proton event in December 2006

The variations in the rigidity spectrum and anisotropy of cosmic rays in December 2006 have been studied based on the surface measurements of the cosmic ray intensity at the global network of stations, using the method of global spectrographic survey. It has been indicated that the highest degree of anisotropy (to ～50%) with the maximal intensity of particles with a rigidity of 4 GV in the direction from the Sun (an asymptotic direction of about ?25° and 160°) was observed at 0400 UT on December 13. The parameters of the cosmic ray rigidity spectrum, which reflect the electromagnetic characteristics of the heliospheric fields during the studied period, have been determined when the surface and satellite measurements of protons in the energy range from several megaelectronvolts to several tens of gigaelectronvolts were jointly analyzed. The observed anisotropy and variations in cosmic rays in a wide energy range have been explained based on an analysis of the results.     

Does an upper limit to river water temperature apply in all places?

There remains continued use of non‐linear, logistic regression models for predicting water temperature from air temperature. A dominant feature of these non‐linear models is an upper bound on river water temperature. This upper bound is often attributed to a large increase in evaporative cooling at high air temperatures, but the exact conditions under which such an increase may occur have not been thoroughly explored. To better understand the appropriateness of the non‐linear model for predicting river water temperatures, it is essential to understand the physical basis for the upper bound and when it should and should not be included in the statistical model. This paper applies and validates an energy balance model against 8 river systems spread across different climate regions of the United States. The energy balance model is then used to develop a diagram relating vapour pressure deficit and air temperature to water temperature. With knowledge of present or future vapour pressure deficit (difference between saturation and actual vapour content in the atmosphere) conditions in a given climate, the diagram can be used to predict the likelihood of an upper bound in the air–water temperature relationship. This investigation offers a fundamental physical explanation of the most appropriate form of statistical models that should be used for predicting future water temperature from air temperature in different geographic regions with different climate conditions. In general, climatic regions that have only a slight increase in vapour pressure deficit with increasing air temperature (typically humid regions) would not be expected to have an upper bound. Conversely, climatic regions in which vapour pressure deficit sharply increases with increasing air temperature (typically arid regions) would be expected to have an upper bound.     

Electromagnetic fields in a steel-cased borehole

The development of an electromagnetic numerical modelling scheme for a magnetic dipole in an arbitrary casing segment in an inhomogeneous conductivity background has been difficult, due to the very high electrical conductivity and magnetic permeability contrasts between the steel casing and the background medium. To investigate the effect of steel casing efficiently, we have developed an accurate but simple finite‐element modelling scheme to simulate electromagnetic fields in a medium of cylindrically symmetric conductivity structures. In order to preserve the cylindrical symmetry in the resulting electromagnetic fields, a horizontal loop current source is used throughout. One of the main advantages of the approach is that the problem is scalar when formulated using the azimuthal electric field, even if the casing is both electrically conductive and magnetically permeable. Field calculations have been made inside the cased borehole as well as in another borehole which is not cased. Careful analyses of the numerical modelling results indicate that the anomaly observed in a cross‐borehole configuration is sensitive enough to be used for tomographic imaging.     

Wavelet-Aggregated Signal in Earthquake Prediction

The concept of aggregated signal is introduced. Quantitatively, an aggregated signal can be defined as the scalar signal: it accumulates in its own variations only those spectral components that are presented simultaneously in each scalar time series of the multidimensional signal to be analyzed. Moreover, an algorithm of aggregation is proposed to suppress the spectral components that are present in any of the scalar components but absent in others (these components can be called local disturbance signals, for instance of technogenic nature). The main purpose of constructing the aggregated signal is to make clearer the common tendency of low-frequency data-flow in geophysical networks, which indicates an increase in collective behavior.It is known that almost all models of the process of earthquake preparation have pointed out an increase in collective behavior of components of geophysical fields in the region of preparation when the coming geocatastrophe has entered its long- and mid-term stages. Long     

Pacific Plate motion and undulations in geoid and bathymetry

Previous studies have shown that the Pacific geoid and gravity fields exhibit lineated anomalies, trending approximately in the direction of absolute plate motion over the underlying mantle. Because the undulations obliquely cross fracture zones they have often been attributed a convective origin. Recently, lithospheric boudinage caused by diffuse extension has been proposed as a possible mechanism. We have examined the undulations in the free-air anomalies, geoid and bathymetry over a portion of the Pacific Plate to determine quantitatively how the undulations are related to plate motion. We compare the observed data to an axisymmetric, sinusoidal undulation defined in an arbitrary frame of reference; in particular, we seek the north pole of this reference frame that maximizes the correlation between data and model. Poles that are close to the Pacific hotspot pole represent copolar undulations possibly related to plate motion. The distance between the best-fitting poles and the hotspot pole is determined as a function of undulation wavelength and reveals several minima (with distance < 10°) for discrete geoid wavebands centered on wavelengths of 160 km, 225 km, 287 km, 400 km, 660 km, 850 km, 1000 km and 1400 km. Bathymetry data have copolar bathymetric expressions as well, giving an implied admittance of 2–3 m/km. The most co-polar geoid/bathymetry undulations (with poles within 2–3° of the average Pacific Euler pole) have wavelengths of 280 km and 1050 km, respectively. The latter could have a convective origin or be related to the spacing of hotspot swells. The former may reflect lithospheric boudinage formed in response to diffuse extension, but could also have a dynamic origin since flexural dampening may only have attenuated the bathymetric amplitude by 50% or less. Radiometric dating of volcanic ridges found in the troughs of prominent gravity lineations gives ages that correlate well with documented changes in Pacific and Indo/Australian Plate motion, suggesting the ridges formed in response to intermittent plate boundary stresses and not as a direct consequence of small-scale convection or diffuse extension.     

Spatio-temporal variation in rock exhumation linked to large-scale shear zones in the southeastern Tibetan Plateau

Crustal-scale shear zones are believed to have played an important role in the tectonic and landscape evolution of orogens. However, the variation of long-term rock exhumation between the interior of shear zones and adjacent regions has not been documented in detail. In this study, we obtained new zircon U-Pb, biotite ⁴⁰Ar/³⁹Ar, zircon and apatite(U-Th)/He data, and conducted inverse thermal history modeling from two age-elevation profiles(the Pianma and Tu'er profiles) in the southeastern Tibetan Plateau. Our goal is to constrain the exhumation history of the Gaoligong and Chongshan shear zones and adjacent regions, so as to explore the effect of the shear zones on exhumation and their thermal effect on cooling that should not be ignored. Our results suggest that during the interval of 18–11 Ma the exhumation rates of rocks within the Gaoligong shear zone are anomalously high compared with those outside of. The rapid cooling during 18–11 Ma appears to be restricted to the shear zone, likely due to localized thermal effects of shearing and exhumation. After 11 Ma, both the areas within and outside of the shear zones experienced a similar two-stage exhumation history: slower cooling until the early Pliocene, and then a rapid increase in cooling rate since the early Pliocene. Our results indicate a synchronized exhumation but with spatially varied exhumation rates. Our study also highlights the important role of large-scale shear zones in exposing rocks, and thus the importance of the structural context when interpreting thermochronological data in the southeastern margin of the Tibetan Plateau.     

Water quality assessment by pollution-index method in the coastal waters of Hebei Province in western Bohai Sea, China

Sources of pollution discharges and water quality samples at 27 stations in 2006 in the coastal waters of Hebei Province, western Bohai Sea, have been analyzed in this study. Pollutant loads from industrial sewages have shown stronger impact on the water environment than those from the general sewages. Analysis indicates that pollution of COD is mainly resulted from land-based point pollutant sources. For phosphate concentration, non-point source pollution from coastal ocean (fishing and harbor areas) plays an important role. To assess the water quality conditions, Organic Pollution Index and Eutrophication Index have been used to quantify the level of water pollution and eutrophication conditions. Results show that pollution was much heavier in the dry season than flood season in 2006. Based on COD and phosphate concentrations, results show that waters near Shahe River, Douhe River, Yanghe River, and Luanhe River were heavily polluted. Water quality in the Qinhuangdao area was better than those in the Tangshan and Cangzhou areas.