Verification of a scattering-based algorithm for estimating rainfall over the open ocean

Summary An algorithm for estimating rainfall (based upon scattering of upwelling radiation at 85 GHz) using the Special Sensor Microwave Imager (SSM/I) 85 GHz sensor data has recently been developed at the National Oceanographic and Atmospheric Administration's Office of Research and Applications (NOAA ORA). Spatial and temporal variability in the differences between simple areal-averaged rainfall estimates from a raingage and satellite-derived estimates are examined. These initial comparisons provide insight into the nature of the differences; however, due to substantial amounts of spatial sampling error in the raingage spatial averages, this approach is ineffective at identifying statistically significant differences.Thus, rainfall estimates for this algorithm are examined over the tropical Pacific using a statistical technique, called the noncontiguous raingage method (NCR), which minimizes spatial sampling error so that the statistical significance of relationships may be determined. The results indicate that, adjusted with calibration coefficients, the ORA algorithm could produce unbiased estimates of areal rainfall for the tropical Pacific region examined in this study.With 8 Figures     

Solar Activity and Algal-bloom Occurrences in the Northern Adriatic Sea: Geomagnetic Connection

Summary The high-speed particle flux (solar wind) escaping from the Sun controls the geomagnetic activity at middle latitudes. The latter is found to be negatively correlated to the difference of atmospheric pressure between January and April averaged out in the area of the Northern Adriatic. This difference is again related to the water volume flowing from the South into the Northern Adriatic Sea and is a necessary (though not sufficient) condition for the occurrence of strong algal-blooms in summer. A physical model involving geomagnetic activity, mean atmospheric pressured difference between latitude 35 °N and 55 °N in the European area and atmospheric pressure difference from winter to spring in the Northern Adriatic basin is proposed. The possibility of predicting the long-term variations of geomagnetic activity allows one to obtain long-term predictions of winter minus spring pressure and therefore indications of the risk of strong summer-time algal-bloom episodes. Received March 29, 1996 Revised February 14, 1997     

RR Lyrae variables in the globular cluster M3 (NGC 5272) — I. BVI CCD photometry

New BVI CCD photometry is presented for 60 RR Lyrae variables in the globular cluster M3. Light curves have been constructed and ephemerides have been (re)-derived for all of them. Four stars (i.e. V29, V136, V155 and V209), although recognized as variables, had no previous period determinations. Also, the period derived for V129 is significantly different from the one published by Sawyer-Hogg. Light curve parameters, i.e. mean magnitudes, amplitudes and rise times, have been derived.   The discussion of these results in the framework of the stellar evolution and pulsation theories will be presented in a forthcoming paper.     

Selected chemical contaminants in surface sediments of Commencement Bay and the Tacoma Waterways, Washington, USA

Eight metals, 21 organic priority pollutants, and 11 other contaminants and contaminant-related sediment characteristics were measured in surface sediments (upper 2 cm) at 21 locations in Commencement Bay and the Tacoma Waterways, Washington. Summary statistics were calculated and statistical approaches (analysis of variance, multiple comparisons tests, cluster analysis and principal component analysis) were applied to subsets of the data to classify sediment contamination. Overall sediment contamination was highest in the Sitcum, City and Hylebos Waterways, intermediate in Commencement Bay, at the entrances to the Tacoma Waterways and in the outer reaches of the Blair and Hylebos Waterways, and lowest at the Blair Waterway turning basin, the mouth of the Puyallup River and at a reference site near Browns Point. High concentrations of some contaminants appeared to be related to proximity to sources of contaminants. Depositional vectors, and chemical adsorption processes may also influence the spatial distribution of sediment contamination in the study area.Results of simple and partial correlation analyses indicate that arsenic, iron and manganese may be more closely associated with the clay fraction, while cadmium, copper and polynuclear aromatic hydrocarbons may be more closely associated with the total organic carbon content of sediments. We were unable to discriminate statistically between the affinity of chromium, lead, zinc and phthalates with the % clay or the total organic carbon content of sediments.     

The effect of Ruppia cirrhosa features on macroalgae and suspended matter in a Mediterranean shallow system

Relationships among chemical–physical features, total gross suspended organic matter, coverage of the seagrass Ruppia cirrhosa and its associated algal community in eight ponds of a saltworks system of western Sicily (Mediterranean Sea) were investigated in spring and summer 2004. All biological features varied both at different levels of seagrass coverage and between seasons. A low algal diversity (46 taxa, 14.75 ± 1.41 on average) was highlighted; algal coverage and species richness showed to be negatively correlated. Ruppia cirrhosa coverage was negatively correlated with algal coverage, but positively correlated with species richness. Moreover, a significant correlation among R. cirrhosa coverage, the availability of suspended matter in the water column and the chlorophyll a concentration was detected.     

Sudden commencements and sudden impulses in geomagnetism: Their diurnal variation in amplitude

Summary Following on the examination of the frequencies of S. Cs. and S. Is. given in a recent paper (1), the diurnal variation of theH-amplitudes at the six stations Cheltenham, Tucson, San Juan, Honolulu, Huancayo and Watheroo during the period 1926–46 is investigated, and in this S. Cs. and S. Is. do not appear to differ greatly in their behaviour. Except in the case of Huancayo, the greatest amplitudes occur near 0h. local time, after which there is a fall to the lowest values about 7h. The S. Is. amplitudes may have a secondary minimum near 18h., but this is not certain.     

Subduction polarity reversal at the junction between the Western Alps and the Northern Apennines, Italy

The controversial relationship between the orogenic segments of the Western Alps and the Northern Apennines is here explored integrating recently published 3D tomographic models of subduction with new and re-interpreted geological observations from the eclogitic domain of the Voltri Massif (Ligurian Alps, Italy), where the two belts joint each other. The Voltri Massif is here described as an extensional domain accommodating the opposing outward migration of the Alpine and Apennine thrust fronts, since about 30–35 Ma. Using tomographic images of the upper mantle and paleotectonic reconstructions, we propose that this extensional setting represents the surface manifestation of an along strike change in polarity of the subducted oceanic slab whose polarity changed laterally in space and in time. Our tectonic model suggests that the westward shift of the Alpine thrust front from the Oligocene onward was the consequence of the toroidal asthenospheric flow induced by the retreat of the Apenninic slab.     

Numerical analysis of projectile penetration and perforation of plain and fiber reinforced concrete slabs

The research presented in this paper deals with the numerical analysis of projectile impact on regular strength concrete (RSC), high‐strength concrete (HSC), and engineered cementitious composites (ECC) using the Lattice Discrete Particle Model (LDPM). The LDPM is chosen in this study as it naturally captures the failure mechanisms at the length scale of coarse aggregate of concrete, and its capabilities include the accurate depiction of both intrinsic and apparent rate effects in concrete, as well as fiber reinforcement effects. The model is used to predict the experimental impact response performed by four independent testing laboratories, and for each data set the model parameters are calibrated and validated using a combination of uniaxial compression, triaxial compression, uniaxial strain compression, and dogbone tests. In the first study, perforation experiments on RSC and HSC for varied impact velocities are carried out, and the exit velocity is compared with the available experimental data. The second study focuses on ECC, where multiple impact of steel and plastic fiber reinforced concrete panels are explored. A third investigation is performed on four RSC panels with varied thicknesses and subjected to the same impact velocity. In this instance, the model is used to predict the penetration depths for the different cases. Finally, in the last study, the response of large‐thickness infinite panels of sizes ranging from 300 mm to 700 mm under projectile impact is considered. Copyright © 2016 John Wiley & Sons, Ltd.