New encoder–decoder convolutional LSTM neural network architectures for next-day global ionosphere maps forecast     

de Paulo  M. C. M.  Marques  H. A.  Feitosa  R. Q.  Ferreira  M. P. 《GPS Solutions》2023,27(2):1-12

GPS Solutions - In addition to traditional tide gauges, the ground-based global navigation satellite system reflectometry (GNSS-R) that utilizes signal-to-noise ratio data from a single GNSS...  相似文献   

Discussion: “Evidence for a transgressive barrier within a regressive strandplain system: implications for complex response to environmental change” by Hein,et al. (2013), Sedimentology 60, 469–502     

Sérgio R. Dillenburg  Eduardo G. Barboza  Patrick A. Hesp  Maria Luiza C.C. Rosa  Rodolfo J. Angulo  Maria C. Souza  Paulo C.F. Giannini  André O. Sawakuchi 《Sedimentology》2014,61(7):2205-2212

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Carbon isotopes and geochemical processes in CO2-rich cold mineral water,N-Portugal     

P. M. Carreira  J. M. Marques  M. R. Carvalho  D. Nunes  M. Antunes da Silva 《Environmental Earth Sciences》2014,71(6):2941-2953

This paper summarizes a new outlook on the conceptual model of Melgaço–Messegães CO₂-rich cold (≈18 °C) mineral water systems, issuing in N of Portugal, based on their isotopic (²H, ³H, ¹³C, ¹⁴C and ¹⁸O) and geochemical features. Stable isotopes indicate the meteoric origin of these CO₂-rich mineral waters. Based on the isotopic fractionation with the altitude, a recharge altitude between 513 up to 740 m a.s.l. was estimated, corroborating the tritium results. The lowest ³H content (0 TU) is found in the groundwater samples with the highest mineralization. The mineral waters circulation are mainly related to a granitic and granodioritic environment inducing two different groundwater types (Ca/Na–HCO₃ and Na/Ca–HCO₃), indicating different underground flow paths. Calcium dissolution is controlled by hydrolysis of rock-matrix silicate minerals (e.g. Ca-plagioclases) and not associated to anthropogenic sources. The shallow dilute groundwaters exhibit signatures of anthropogenic origins (e.g. NO₃) and higher Na/Ca ratios. The stable isotopes together with the geochemistry provided no indication of mixing between the regional shallow cold dilute groundwater and mineral water systems. The heavy isotopic signatures identified in the δ¹³C data (δ¹³C = 4.7 ‰, performed on the total dissolved inorganic carbon (TDIC) of CO₂-rich mineral waters) could be derived from a deep-seated (upper mantle) source or associated to methanogenesis (CH₄ source). The negligible ¹⁴C content (≈2 pmC) determined in the TDIC of the mineral waters, corroborates the hypothesis of a mantle-derived carbon source to the mineral groundwater systems or dissolution of carbonate layers at depth.  相似文献   

Numerical modelling assessment of climate-change impacts and mitigation measures on the Querença-Silves coastal aquifer (Algarve,Portugal)     

Rui Hugman  Tibor Stigter  Luis Costa  José Paulo Monteiro 《Hydrogeology Journal》2017,25(7):2105-2121

Predicted changes in climate will lead to seawater intrusion in the Querença-Silves (QS) coastal aquifer (south Portugal) during the coming century if the current water-resource-management strategy is maintained. As for much of the Mediterranean, average rainfall is predicted to decrease along with increasing seasonal and inter-annual variability and there is a need to understand how these changes will affect the sustainable use of groundwater resources. A density-coupled flow and transport model of the QS was used to simulate an ensemble of climate, water-use and adaptation scenarios from 2010 to 2099 taking into account intra- and inter-annual variability in recharge and groundwater use. By considering several climate models, bias correction and recharge calculation methods, a degree of uncertainty was included. Changes in rainfall regimes will have an immediate effect on groundwater discharge; however, the effect on saltwater intrusion is attenuated by the freshwater–saltwater interfaces’ comparatively slow rate of movement. Comparing the effects of adaptation measures demonstrates that the extent of intrusion in the QS is controlled by the long-term water budget, as the effectiveness of both demand and supply oriented measures is proportional to the change in water budget, and that to maintain the current position, average groundwater discharge should be in the order of 50 × 10⁶ m³ yr^?1.  相似文献