Diffuse volcanic gas emission and thermal energy release from the summit crater of Pico do Fogo,Cape Verde     

Samara M. Dionis  Gladys Melián  Fátima Rodríguez  Pedro A. Hernández  Eleazar Padrón  Nemesio M. Pérez  Jose Barrancos  Germán Padilla  Hirochika Sumino  Paulo Fernandes  Zuleyka Bandomo  Sónia Silva  José M. Pereira  Hélio Semedo 《Bulletin of Volcanology》2015,77(2):1-13

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Comparative analysis of rating curve and ADP estimates of instantaneous water discharge through estuaries in two contrasting Brazilian rivers     

Francisco José da Silva Dias  Luiz Drude Lacerda  Rozane Valente Marins  Francisco Carlos Fernandes de Paula 《水文研究》2011,25(14):2188-2201

This work quantifies, using ADP and rating curve techniques, the instantaneous outflows at estuarine interfaces: higher to middle estuary and middle to lower estuary, in two medium‐sized watersheds (72 000 and 66 000 km² of area, respectively), the Jaguaribe and Contas Rivers located in the northeastern (semi‐arid) and eastern (tropical humid) Brazilian coasts, respectively. Results from ADP showed that the net water balances show the Contas River as a net water exporter, whereas the Jaguaribe River Estuary is a net water importer. At the Jaguaribe Estuary, water retention during flood tide contributes to 58% of the total volume transferred during the ebb tide from the middle to lower estuary. However, 42% of the total water volume (452 m³ s^?1) that entered during flood tide is retained in the middle estuary. In the Contas River, 90% of the total water is retained during the flood tide contributing to the volume transported in the ebb tide from the middle to the lower estuary. Outflows obtained with the rating curve method for the Contas and Jaguaribe Rivers were uniform through time due to river flow normalization by dams in both basins. Estimated outflows with this method are about 65% (Contas) and 95% (Jaguaribe) lower compared to outflows obtained with ADP. This suggests that the outflows obtained with the rating curve method underestimate the net water balance in both systems, particularly in the Jaguaribe River under a semi‐arid climate. This underestimation is somewhat decreased due to wetter conditions in the Contas River basin. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

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

P Amol  D Shankar  V Fernando  A Mukherjee  S G Aparna  R Fernandes  G S Michael  S T Khalap  N P Satelkar  Y Agarvadekar  M G Gaonkar  A P Tari  A Kankonkar  S P Vernekar 《Journal of Earth System Science》2014,123(5):1045-1074

We present current data from acoustic Doppler current profilers (ADCPs) moored on the continental slope off the west coast of India. The data were collected at four locations (roughly at Kanyakumari, Kollam, Goa, and Mumbai) extending from ～ 7° to ～ 20°N during 2008–2012. The observations show that a seasonal cycle, including an annual cycle, is present in the West India Coastal Current (WICC); this seasonal cycle, which strengthens northward, shows considerable interannual variability and is not as strongly correlated along the coast as in climatologies based on ship drifts or the altimeter. The alongshore decorrelation of the WICC is much stronger at intraseasonal periods, which are evident during the winter monsoon all along the coast. This intraseasonal variability is stronger in the south. A striking feature of the WICC is upward phase propagation, which implies an undercurrent whose depth becomes shallower as the season progresses. There are also instances when the phase propagates downward. At the two southern mooring locations off Kollam and Kanyakumari, the cross-shore current, which is usually associated with eddy-like circulations, is comparable to the alongshore current on occasions. A comparison with data from the OSCAR (Ocean Surface Currents Analyses Real-time) data product shows not only similarities, but also significant differences, particularly in the phase. One possible reason for this phase mismatch between the ADCP current at 48 m and the OSCAR current, which represents the current in the 0–30 m depth range, is the vertical phase propagation. Current products based on Ocean General Circulation Models like ECCO2 (Estimating the Circulation and Climate of the Ocean, Phase II) and GODAS (Global Ocean Data Assimilation System) show a weaker correlation with the ADCP current, and ECCO2 does capture some of the observed variability.  相似文献   

Characterizing slope morphology using multifractal technique: a study from the western continental margin of India     

Bishwajit Chakraborty  S. M. Karisiddaiah  A. A. A. Menezes  K. Haris  G. S. Gokul  W. Fernandes  G. Kavitha 《Natural Hazards》2014,73(2):547-565

Here, we present the slope configuration of the submarine gullies, ridges and the adjacent slump zone off Goa, along the western continental margin of India utilizing multibeam bathymetric and single-channel seismic data. The fluid flow migration signature in the form of pockmark seepages, traces of mud volcanoes and enhanced reflectors is observed in the area. Altogether thirty-three depth profiles from the gully, ridge and slump areas depict downslope progression in gully incision and varying gradients in the gullies (1.19–4.07°) and ridges (2.13–3.70°), whereas the profiles of the slump zone are comparatively steady (2.25–2.51°). The scatter plot of the three slope characteristics, viz., gradient, mean depth and root mean square relief, characterizes the profiles of the gullies, ridges and slump zone into three distinct clusters. Principal component analysis as well corroborates the categorization. Furthermore, a stochastic multifractal technique has been employed to understand the nature of the fine-scale seafloor processes active in the slope region. The three estimated parameters of the depth profiles, i.e., the degree of multifractality (α), sparseness (C ₁) and the degree of smoothness (H), substantiate a very high degree of multifractality for all the thirty-three bathymetric profiles. Except for the five adjacent profiles (four from the slump zone and one from the ridge), the remaining twenty-eight depth profiles of the gully, ridges and slump zones show negligible difference. Based on the multifractal study, we conclude that the observed discrimination might be due to the significant interaction between the bottom currents off Goa and the varied seafloor morphological aspects with seepages and faults.  相似文献   

Depositional environment of mudflats and mangroves and bioavailability of selected metals within mudflats in a tropical estuary   总被引：1，自引：1，他引：0  

M. C. Fernandes  G. N. Nayak  A. Pande  S. P. Volvoikar  D. R. G. Dessai 《Environmental Earth Sciences》2014,72(6):1861-1875

Four sediment cores representing adjacent mudflat and mangrove sub-environments of middle estuary (Shastri) were analyzed for sand, silt, clay, and organic carbon. Total metal concentration of iron (Fe), manganese (Mn), nickel (Ni), zinc (Zn), chromium (Cr), copper (Cu), cobalt (Co), and lead (Pb) and chemical speciation of Fe, Mn, and Co on selected samples was also carried out on mudflat cores. The sediments in the upper middle estuary were found to be deposited under highly varying hydrodynamic energy conditions; whereas lower middle estuary experienced relatively stable hydrodynamic energy conditions with time. The tributary joining the river near the upper middle estuary is found to be responsible for the addition of enhanced organic carbon and metal concentrations. Speciation study indicated Fe and Co are from natural lithogenic origin while Mn is derived from anthropogenic sources. Higher Mn and Co than apparent effects threshold can pose a high risk of toxicity to organisms associated with these sediments.  相似文献   

Identifying biologically and physically special or unique sites for inclusion in the protected area design for the Great Barrier Reef Marine Park     

Leanne Fernandes  Kirstin Dobbs  Jon Day  Suzanne Slegers 《Ocean & Coastal Management》2010,53(2):80-88

A method to identify special and/or unique sites was developed when reviewing the zoning of the Great Barrier Reef Marine Park. Fifty-three (totalling approximately 10,445 km²) of 408 sites were identified as special or unique based on the amount, detail and nature of justification; geographic explicitness; type of information sources; number of independent sources; and national or international obligations. All but four special or unique sites increased in protection after the Zoning Plan was revised, increasing the area of no-take protection for all special or unique sites from 1614 km² (15.4%) to 4013 km² (38.4%).  相似文献   

The Science Operations Centre of MINISAT-01     

Antonio Talavera  Jesús García  Carlos Quintana  Eduardo Fernandes 《Astrophysics and Space Science》2001,276(1):89-96

The Scientific Operations Centre (C.O.C.) takes care of all aspects of theMinisat-01 Mission related to the payload and its scientific instruments. Operations planning, preparation of commands, monitoring of the scientific instruments and data processing and distribution are the daily tasks carried out at the COC. We review these tasks along the operational life of Minisat-01 and we present a summary of the science operations andsome statistics on the usage of the satellite.  相似文献   

The nature of the HE0450−2958 system     

David Merritt  Thaisa Storchi-Bergmann  rew Robinson  Dan Batcheldor  David Axon  Roberto Cid Fernandes 《Monthly notices of the Royal Astronomical Society》2006,367(4):1746-1750

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Slit observations and empirical calculations for H ii regions     

I. F. Fernandes  R. Gruenwald  S. M. Viegas 《Monthly notices of the Royal Astronomical Society》2005,364(2):674-682

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Stellar population gradients in Seyfert 2 galaxies: northern sample     

D. Raimann  T. Storchi-Bergmann  R. M. González Delgado  R. Cid Fernandes  T. Heckman  C. Leitherer  H. Schmitt † 《Monthly notices of the Royal Astronomical Society》2003,339(3):772-792

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