Observed seasonal and intraseasonal variability of the East India Coastal Current on the continental slope

We present data from three acoustic Doppler current profilers (ADCPs) moored off Cuddalore (12^°N), Kakinada (16.5^°N), and Gopalpur (19^°N) on the continental slope of the western Bay of Bengal and one mooring on the slope of the northern bay (89^°E, 19^°N; referred to as being located at Paradip). The data were collected during May 2009 to March 2013 and the observations show that the seasonal cycle, which includes the annual cycle, the semi-annual cycle, and a peak around 120 days, dominates the observed variability of the East India Coastal Current (EICC). Spectral analysis suggests that the 120-day peak dominates the seasonal variability at Paradip and is strong at Gopalpur and Kakinada. The annual cycle is coherent along the western boundary of the bay, i.e., the east coast of India, but with significant phase differences between moorings. At the semi-annual and 120-day periods, the alongshore coherence is weaker. Intraseasonal variability is weaker than the seasonal cycle, particularly at Cuddalore and Paradip, and it exhibits seasonality: the strongest intraseasonal variation is during spring (February–April). Peaks around 12 and 20–22 days are also seen at Gopalpur, Kakinada, and Cuddalore. A striking feature of the currents is the upward phase propagation, but there are also instances when phase propagates downward. The much lower vertical phase speed in the top ～100 m at Cuddalore leads to a distinct undercurrent at this location; at other locations, the undercurrent, though it exists often, is not as striking. During spring, however, the EICC tends to flow poleward (eastward) at Cuddalore, Kakinada, and Gopalpur (Paradip) over the top ～300 m, which is the maximum depth to which observations were made. The cross-shore component of the EICC is much weaker than the alongshore component at Cuddalore and, except for a few bursts during spring, at Kakinada and Gopalpur. It is only at Paradip, on the slope of the northern boundary, that significant cross-shore flows are seen during spring and the summer monsoon (June–August) and these flows are seen to be associated with eddy-like circulations in the altimeter data. We use the ADCP data to validate popular current data products like OSCAR (Ocean Surface Currents Analyses Real-time), ECCO2 (Estimating the Circulation and Climate of the Ocean, Phase II), and GODAS (Global Ocean Data Assimilation System). The OSCAR currents at Paradip match the observed currents well, but the correlation is much weaker at the other three locations. Both ECCO2 and GODAS fair poorly, particularly the latter because its variability in this boundary-current regime is extremely weak. Though it performs badly at Paradip, ECCO2 does capture the observed variability on occasions at the other locations.     

A Review of “India's New Economic Policy: A Critical Analysis”

Entering overseas markets provides challenges for firms, especially for those with little international experience. These obstacles can be compounded for manufacturers of advanced machinery, as previous research suggests that a physical presence is necessary for the successful implementation of their products in export markets. One way for producers to address this issue is to participate in trade fairs, which enables a physical presence of staff and machinery to be established. Evidence from a survey of Korean machinery producers at a recent trade fair suggests that a physical presence is related to the importance that firms ascribe to exports and to the role of trade fairs in new sales.     

A multifrequency maximum-entropy joint analysis of COBE and Tenerife data

We use data from the Tenerife 10-, 15- and 33‐GHz beam-switching experiments along with the COBE 53- and 90‐GHz data to separate the cosmic microwave background (CMB) signal from the Galactic signal, and create two maps at high Galactic latitude. The new multi-MEM technique is used to obtain the best reconstruction of the two channels. The two maps are presented, and known features are identified within each. We find that the Galactic contribution to both the 15- and 33-GHz Tenerife data is small enough to be ignored when compared with the errors in the data and the magnitude of the CMB signal.     

Polybrominated diphenyl ethers do not affect metamorphosis but alter the proteome of the invasive slipper limpet Crepidula onyx

Man-made polybrominated diphenyl ethers (PBDEs) used as flame retardants in various consumer products may be harmful to marine organisms. Larvae of some marine invertebrates, especially invasive species, can develop resistance to PBDEs through altered protein expression patterns or proteome plasticity. This is the first report of a proteomics approach to study BDE-47 induced molecular changes in the invasive limpet Crepidula onyx. Larvae of C. onyx were cultured for 5 days (hatching to metamorphosis) in the presence of BDE-47 (1 μg L⁻¹). Using a 2-DE proteomics approach with triple quadrupole and high-resolution TOF-MS, we showed that BDE-47 altered the proteome structure but not the growth or metamorphosis of C. onyx larvae. We found eight significant differentially expressed proteins in response to BDE-47, deemed the protein expression signature, consisting of cytoskeletal, stress tolerance, metabolism and energy production related proteins. Our data suggest C. onyx larvae have adequate proteome plasticity to tolerate BDE-47 toxicity.     

Assessment of Hurricane Ivan impact on chlorophyll-a in Pensacola Bay by MODIS 250 m remote sensing

The impact of Hurricane Ivan on water quality in Pensacola Bay was investigated by MODIS 250 m remote sensing of chlorophyll-a concentrations at different time slots before and after the hurricane event. Before the hurricane, the mean chlorophyll-a in the Bay was 5.3 μg/L. Heavy rainfall occurred during the hurricane landfall. The 48 h rainfall reached 40 cm and the peak storm surge reached 3 m on 9/16. After the rainstorm and during the storm surge on 9/17/2004, the mean chlorophyll-a concentration substantially increased to 14.7 μg/L. 26.3% water area was in the poor-water-quality condition (chl-a > 20 μg/L). This indicates that heavy nutrient loads from urban stormwater runoff and storm-surge inundation simulated chlorophyll bloom. After the end of the storm surge on 9/18/2004, the mean chlorophyll dropped to 2.0 μg/L, suggesting the effective flushing of polluted water from the bay to the Gulf of Mexico by the storm-surge. The good water quality condition lasted for almost several weeks after the storm surge. The peak river flow, arriving on the 4th day after the peak storm surge, did not alter the good water quality situation in the bay. This indicates that urban stormwater runoff rather than the river inflow is the major pollutant source for water quality in Pensacola Bay during the hurricane.     

Structure and dynamics of undercurrents in the western boundary current of the Bay of Bengal

Ocean Dynamics - The structure and variability of undercurrents in the East India Coastal Current (EICC), which is the western boundary current system in the Bay of Bengal (BoB), and the mechanisms...     

GIS use by an urban local body as part of e-governance in India

Government organizations in the developing world have been at the forefront of ongoing reforms that have prompted their use of GIS and other information and communication technologies for urban governance. However, there have been very few examinations of GIS spatial knowledge construction in a non-Western context. Particularly, very little is known about the growing and varying use of GIS and spatial information by urban local bodies in India in the midst of India’s changing urban governance culture. This article presents an in-depth examination of Surat Municipal Corporation (SMC), one of India’s leading urban local bodies as the corporation implements e-governance strategies including the use of GIS and spatial information. Drawing from Critical GIS literature and GIS implementation and diffusion literature, this article uses an integrated approach to examine SMC’s GIS spatial knowledge construction. The article demonstrates that in the case of SMC, GIS knowledge construction is not only shaped by SMC’s proactive role in positioning itself with the national government’s priorities and agendas, but also by the presence of powerful actors who play an instrumental role in introducing change and innovation. This article is part of a larger project that aims to investigate the process of GIS spatial knowledge construction situated in contemporary India.     

Elevated naturally occurring arsenic in a semiarid oxidizing system, Southern High Plains aquifer, Texas, USA

High groundwater As concentrations in oxidizing systems are generally associated with As adsorption onto hydrous metal (Al, Fe or Mn) oxides and mobilization with increased pH. The objective of this study was to evaluate the distribution, sources and mobilization mechanisms of As in the Southern High Plains (SHP) aquifer, Texas, relative to those in other semiarid, oxidizing systems. Elevated groundwater As levels are widespread in the southern part of the SHP (SHP-S) aquifer, with 47% of wells exceeding the current EPA maximum contaminant level (MCL) of 10 μg/L (range 0.3–164 μg/L), whereas As levels are much lower in the north (SHP-N: 9%  As MCL of 10 μg/L; range 0.2–43 μg/L). The sharp contrast in As levels between the north and south coincides with a change in total dissolved solids (TDS) from 395 mg/L (median north) to 885 mg/L (median south). Arsenic is present as arsenate (As V) in this oxidizing system and is correlated with groundwater TDS (Spearman’s ρ = 0.57). The most likely current source of As is sorbed As onto hydrous metal oxides based on correlations between As and other oxyanion-forming elements (V, ρ = 0.88; Se, ρ = 0.54; B, ρ = 0.51 and Mo, ρ = 0.46). This source is similar to that in other oxidizing systems and constitutes a secondary source; the most likely primary source being volcanic ashes in the SHP aquifer or original source rocks in the Rockies, based on co-occurrence of As and F (ρ = 0.56), oxyanion-forming elements and SiO₂ (ρ = 0.41), which are found in volcanic ashes. High groundwater As concentrations in some semiarid oxidizing systems are related to high evaporation. Although correlation of As with TDS in the SHP aquifer may suggest evaporative concentration, unenriched stable isotopes (δ²H: −65 to −27; δ¹⁸O: −9.1 to −4.2) in the SHP aquifer do not support evaporation. High TDS in the SHP aquifer is most likely related to upward movement of saline water from the underlying Triassic Dockum aquifer. Mobilization of As in other semiarid oxidizing systems is caused by increased pH; however, pH in the SHP aquifer is near neutral (10–90 percentiles, 7.0–7.6). Although many processes, such as competitive desorption with SiO₂, VO₄, or PO₄, could be responsible for local mobilization of As in the SHP aquifer, the most plausible explanation for the regional As distribution and correlation with TDS is the counterion effect caused by a change from Ca- to Na-rich, water as shown by the high correlation between As and Na/(Ca)^0.5 ratios (ρ = 0.57). This change in chemistry is related to mixing with saline water that moves upward from the underlying Dockum aquifer. This counterion effect may mobilize other anions and oxyanion-forming elements that are correlated with As (F, V, Se, B, Mo and SiO₂). Competition among the oxyanions for sorption sites may enhance As mobilization. The SHP case study has similar As sources to those of other semiarid, oxidizing systems (original volcanic ash source followed by sorption onto hydrous metal oxides) but contrasts with these systems by showing lack of evaporative concentration and pH mobilization of As but counterion mobilization of As instead in the SHP-S aquifer.     

Petrogenesis of S-type Ladakh granite and mafic microgranular enclaves in the southern margin of Ladakh batholith: An evidence of crust–mantle interaction during the collision between Indian and Eurasian plates

The previous studies revealed the I-type Ladakh magmatism in the Andean-type southern margin of the Ladakh batholith (LB) was related to the subduction of the Neotethyan Ocean and India-Eurasia collision. However, LB's S-type granitic magmatism and associated mafic microgranular enclaves (MMEs) are poorly constrained. Here, we present the new data for S-type Ladakh granite (LG) and associated monzodiorite MMEs in the Andean-type orogeny in the southern margin of the Eurasian plate. The low SiO₂ (47.4–53.9 wt%), high K₂O (1.56–3.21 wt%), Mg^# (52–65), continental-arc tracer patterns, and slightly depleted to evolved Sr-Nd isotopic composition ((⁸⁷Sr/⁸⁶Sr)i = 0.7047–0.7166; ℇ_Nd (t = 50 Ma) = (+1.40 to −8.92)) for MME suggest that they were derived from the phlogopite-bearing deep lithospheric mantle-source at a depth of 5.4–10.5 km depth with 810–870°C, 1.4–2.8 kbar, and enriched by sediment-melts addition into the mantle-wedge from subducting Neotethyan Oceanic slab. The mantle-derived ascending hot mafic magma mixing with felsic magma of the ancient northern Indian margin-derived, generates monzodiorite MME by assimilation and magma mixing processes. Plagioclase, amphibole, and biotite chemistry support the magma mixing processes. LG are characterized by high SiO₂ (63.4–75.0 wt%), K₂O (3.93–5.67 wt%), CaO/Na₂O ratio of >0.3, differentiation index (90.27–97.46), normative corundum (1.0–2.8), A/CNK values (1.00–1.18), hypersthene (0.7–5.7), and low Al₂O₃, MgO, TiO₂, Fe₂O₃. They also exhibit peraluminous, variable tracer elemental abundances, variable (⁸⁷Sr/⁸⁶Sr)i ratios (0.6967–0.7191), and high whole rock ℇ_Nd (t = 50 Ma) values of −4.15 to −11.92) and ancient two-stage Nd model age of 1160 and 1858 Ma. These features suggest that S-type Ladakh granites were derived from the melting of ancient metagreywacke-dominated metasedimentary rocks of the northern Indian margin by a large amount of mafic magma underplating after subducted Neotethyan slab-rollback. The formation of LG and MMEs related to the Andean-type orogeny in the southern margin of the Eurasian plate.     

Approximate analysis of natural vibrations of coupled shear walls

The continuous connection technique is used to analyse the free vibrations of a system of coupled shear walls. The dynamic equation is expressed in integro-differential form, and the natural modes and frequencies are determined by the Galerkin method. Theoretical results are compared with published experimental data.