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Projections of the impacts of climate change on the water deficit and on the precipitation erosive indexes in Mantaro River Basin, Peru

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Journal of Mountain Science 2018年第2期15卷 264-279页

作者： Sly C.WONGCHUIG Carlos R.MELLO Sin C.CHOU Hydraulics institute research Federal University of Rio Grande do Sul Soil and Water Engineering Federal University of Lavras brazilian Weather research and Forecast National Spatial Research Institute (INPE)

Projections of climate change are essential to guide sustainable development plans in the tropical Andean countries such as Peru. This study assessed the projections of precipitation and potential evaporation, rain erosive potential, and precipitation concentration in the Mantaro River Basin, in the Peruvian Andes, which is important for agriculture and energy production in Peru. We assumed the Intergovernmental Panel on Climate Change （IPCC） AIB greenhouse gas emission scenario and simulated the global climate change by the HadCM3 global climate model. Due to the steepness of the mountain slopes and the narrowness of the river valley, this study uses the downscaling of the global model simulations by the regional Eta model down to 2o-km resolution. The downscaling projections show decrease in the monthly precipitation with respect to the baseline period, especially during the rainy season, between February and April, until the end of the 21st century. Meanwhile, a progressive increase in the monthly evaporation from the baseline period is projected. The Modified Fournier Index （MFI） shows a statistically significant downward trend in the Mantaro River Basin, whieh suggests a possible reduction in the rain erosive potential. The Precipitation Concentration Index （PCI） shows a statistically significant increasing trend, which indicates increasingly more irregular temporal distribution of precipitation towards the end of the century. The results of this study allow us to conclude that there should be a gradual increase in water deficit and precipitation concentration. Both changes can be negative for agriculture, power generation, and water supply in the Mantaro River Basin in Peru.

关键词： Precipitation Evaporation PrecipitationConcentration Index (PCI) Modified Fournier Index(MFI) Climate change Tropical Andes

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Spectral classification of water masses under the influence of the Amazon River plume

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Acta Oceanologica Sinica 2010年第3期29卷 1-8页

作者： Gustavo Souto Fontes Molleri Milton Kampel Evlyn Mrcia Leo de Moraes Novo National institute for space research-inpe Remote Sensing Division So Jos dos Campos

The large amount of dissolved and particulate material discharged by the Amazon River into the Equatorial Atlantic Ocean cause distinct spectral response of its waters as compared to the nearby ocean waters. This paper shows the application of K-means clustering algorithm for classifying water masses in the region under the Amazon River plume influence according to their spectral behavior. Salinity and temperature data from 67 oceanographic stations were related to Sea-viewing Wide Field-of-view Sensor （SeaWiFS） remote sensing reflectances values and the following bio-optical products：（i） chlorophyll-a concentration, （ii） water attenuation coefficient and （iii） absorption coefficient for dissolved and detrital material. Four different water masses were identified such as：（1） oceanic water, （2） intermediate oceanic water, （3） intermediate river plume water and （4） Amazon River plume water. The spectral behavior of these water masses allowed concluding that the main active optical component of the waters in the region is the colored dissolved organic matter originated mostly from the Amazon River.

关键词： ocean color remote sensing amazon river plume spectral behavior cluster analysis

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Numerical Simulation of a Liquid Propellant Rocket Motor

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Journal of Thermal Science 2001年第1期10卷 83-86页

作者： Nicolas M.C. Salvador, Marcelo M. Morales, Carlos E.S.S. Migueis, Demetrio Bastos-Netto (inpe - National institute for space research, Rod. Presidente Dutra km 40, Cachoeira Paulista, SP, Brazil 12630-000., e-mail:demetrio@yabae,cptec.inpe.br) inpe - National institute for space research Cachoeira Paulista SP Brazil

This work presents a numerical simulation of the flow field in a liquid propellant rocket engine chamber and exit nozzle using techniques to allow the results to be taken as starting points for designing those propulsive systems. This was done using a Finite Volume method simulating the different flow regimes which usually take place in those systems. As the flow field has regions ranging from the low subsonic to the supersonic regimes, the numerical code used, initially developed for commpressible flows only, was modified to work proficiently in the whole velocity range. It is well known that codes have been developed in CFD, for either compressible or incompressible flows, the joint treatment of both together being complex even today, given the small number of. references available in this area. Here an existing code for compressible flow was used and primitive variables, the pressure, the Cartesian components of the velocity and the temperature instead of the conserved variables were introduced in the Euler and Navier-Stokes equations. This was done to penult the treatment at any Mach number. Unstructured meshes with adaptive refinements were employed here. The convective terms were treated with upwind first and second order methods. The numerical stability was kept with artificial dissipation and in the spatial coverage one used a five stage Runge-Kutta scheme for the Fluid Mechanics and the VODE (Value of Ordinary Differential Equations) scheme along with the Chemkin II in the chemical reacting solution. During the development of this code simulating the flow in a rocket engine, comparison tests were made with several different types of internal and external flows, at different velocities, seeking to establish the confidence level of the techniques being used. These comparisons were done with existing theortical results and with other codes already validated and well acceptal by the CFD community.

关键词： numerical ximulation liquid propellant rocket CFD.

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Study of fluctuations in the Martian magnetosheath using a kurtosis technique:Mars Express observations

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Earth and Planetary Physics 2022年第1期6卷 28-41页

作者： A.M.S.Franco E.Echer M.J.A.Bolzan M.Fraenz National institute for space research(inpe) Sao Jose dos CamposBrazil Federal University of Jatai JataiBrazil Max Planck institute for Solar System research GöttingenGermany

Planetary magnetosheaths are characterized by high plasma wave and turbulence *** Martian magnetosheath is no exception;both upstream and locally generated plasma waves have been observed in the region between its bow shock and magnetic boundary layer,its induced *** statistical study of wave activity in the Martian magnetosheath is based on 12 years(2005-2016)of observations made during Mars Express(MEX)crossings of the planet’s magnetosheath-in particular,data on electron density and temperature data collected by the electron spectrometer(ELS)of the plasma analyzer(ASPERA-3)experiment on board the MEX spacecraft.A kurtosis parameter has been calculated for these plasma *** value indicates intermittent behavior in the data when it is higher than 3(the value for a normal or Gaussian distribution).The variation of wave activity occurrence has been analyzed in relation to solar cycle,Martian orbit,and distance to the bow ***-Gaussian properties are observed in the magnetosheath of Mars on all analyzed scales,especially in those near the proton gyrofrequency in the upstream region of the Martian *** also report that non-Gaussian behavior is most prominent at the smaller scales(higher frequencies).A significant influence of the solar cycle was also observed;the kurtosis parameter is higher during declining and solar maximum phases,when the presence of disturbed solar wind conditions,caused by large scale solar wind structures,*** kurtosis decreases with increasing distance from the bow shock,which indicates that the intermittence level is higher near the bow *** the electron temperature data the kurtosis is higher near the perihelion due to the higher incidence of EUV when the planet is closer to the Sun,which causes a more extended exosphere,and consequently increases the wave activity in the magnetosheath and its upstream *** extended exosphere seems to play a lower effect in the electron den

关键词： Mars magnetosheath kurtosis ULF waves

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Lightning Changes in Response to Global Warming in Rio de Janeiro, Brazil

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American Journal of Climate Change 2020年第3期9卷 266-273页

作者： Osmar Pinto Jr. Iara R. C. A. Pinto brazilian institute of space research (inpe) S. J. dos Campos Brazil

Physical concepts based on the Clausius-Clapeyron relation and on the thermodynamics and aerosol characteristics associated with updrafts, global climate models assuming different parametrizations and lightning-related output variables, and lightning-related data (thunderstorm days) are being used to infer the lightning incidence in a warmer planet, motivated by the global warming observed. In all cases, there are many gaps to be overcome making the lightning response to the global temperature increase still unpredicted. Values from almost 0% (no increase) to 100% have been estimated, being 10% the most common value. While the physical concepts address only part of the problem and the global climate models need to make many simple assumptions, lightning-relate data have strong time and space limitations. In this context, any new evidence should be considered as an important contribution to better understand how will be the lightning incidence in the future. In this article, we described new results about the occurrence of thunderstorms from 1850 to 2010 (a period of 160 years) in the city of Rio de Janeiro, in the Southeast of Brazil. During this period thunderstorm days were recorded in the same location, making this time series one of the longest series of this type available worldwide. The data support an increase of 21% in the mean annual thunderstorm days during the period, while surface temperature increased by 0.6space:normal;orphans:2;flo

关键词： Lightning Global Change Rio de Janeiro Brazil

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Artificial equilibrium points and bi-impulsive maneuvers to observe 243 Ida

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Chinese Journal of Aeronautics 2021年第1期34卷 410-423页

作者： Allan Kardec de ALMEIDA Jr Geraldo Magela Couto OLIVEIRA Antonio Fernando Bertachini de Almeida PRADO National institute for space research(inpe) Sao Jose dos Campos 12227-010Brazil Federal Center for Technological Education of Minas Gerais(CEFET-MG) Belo Horizonte 30421-169Brazil

In the restricted three-body problem,the traditional Lagrange points L1 and L2 are the only equilibrium points near the asteroid 243 *** thrust generated by a solar sail over a spacecraft enables the existence of new artificial equilibrium points,which depend on the position of the spacecraft with respect to the asteroid and the attitude of the solar *** equilibrium points generate new spots to observe the body from above or below the plane of *** points are very good observational locations due to their stationary *** work provides a preliminary analysis to observe Ida through the use of artificial equilibrium points as spots combined with transfer maneuvers between *** combination can be used to observe the asteroid from more different points of view in comparison to fixed *** analyses are made for a spacecraft equipped with a solar sail and capable of performing bi-impulsive *** solar radiation pressure is used both to maintain the equilibrium condition and to reduce the costs of the transfers and/or to create transfers with longer *** is a new aspect of the present research,because it combines the continuous thrust with initial and final small impulses,which are feasible for most of the spacecraft,because the magnitudes of the impulses are very *** combined maneuvers may reduce the transfer times of the maneuvers in most of the cases,compared with the maneuvers based only on continuous *** options involved in these transfers are shown,like to minimize the fuel spent(Dv)as a function of the transfer time or to extend the duration of the travel between the *** transfer times can be useful when observations are required during the transfers.

关键词： Artificial equilibrium points Astrodynamics Orbital transfers Solar radiation pressure Solar sail

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Systematic Review on Ground-Based Cloud Tracking Methods for Photovoltaics Nowcasting

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American Journal of Climate Change 2024年第3期13卷 452-476页

作者： Juliana Marian Arrais Allan Cerentini Bruno Juncklaus Martins Thiago Zimmermann Loureiro Chaves Sylvio Luiz Mantelli Neto Aldo von Wangenheim PPGCC-INE UFSC Federal University of Santa Catarina Florianpolis Brazil inpe brazilian National institute for space research So Paulo Brazil

Renewable energies are highly dependent on local weather conditions, with photovoltaic energy being particularly affected by intermittent clouds. Anticipating the impact of cloud shadows on power plants is crucial, as clouds can cause partial shading, excessive irradiation, and operational issues. This study focuses on analyzing cloud tracking methods for short-term forecasts, aiming to mitigate such impacts. We conducted a systematic literature review, highlighting the most significant articles on cloud tracking from ground-based observations. We explore both traditional image processing techniques and advances in deep learning models. Additionally, we discuss current challenges and future research directions in this rapidly evolving field, aiming to provide a comprehensive overview of the state of the art and identify opportunities for significant advancements in the next generation of cloud tracking systems based on computer vision and deep learning.

关键词： Nowcasting Photovoltaic Image Processing

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Climate Precipitation Prediction by Neural Network

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Journal of Mathematics and System Science 2015年第5期5卷 207-213页

作者： Juliana Aparecida Anochi Haroldo Fraga de Campos Velho Applied Computing Graduate Program National Institute for Space Research (INPE) Brazil. Associated Laboratory for Computing and Applied Mathematics National Institute for Space Research (INPE).

In this work a neural network model for climate forecasting is presented. The model is built by training a neural network with available reanalysis data. In order to assess the model, the development methodology considers the use of data reduction strategies that eliminate data redundancy thus reducing the complexity of the models. The results presented in this paper considered the use of Rough Sets Theory principles in extracting relevant information from the available data to achieve the reduction of redundancy among the variables used for forecasting purposes. The paper presents results of climate prediction made with the use of the neural network based model. The results obtained in the conducted experiments show the effectiveness of the methodology, presenting estimates similar to observations.

关键词： Climate Prediction Neural Networks Rough Sets Theory

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Segmentation and Classification of Individual Clouds in Images Captured with Horizon-Aimed Cameras for Nowcasting of Solar Irradiance Absorption

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American Journal of Climate Change 2023年第4期12卷 628-654页

作者： Bruno Juncklaus Martins Juliana Marian Arrais Allan Cerentini Aldo von Wangenheim Gilberto Perello Ricci Neto Sylvio Mantelli PPGCC-INE UFSC Federal University of Santa Catarina Florianopolis Brazil FOTOVOLTAICA INPE Brazilian National Institute for Space Research Sao Paulo Brazil

One important aspect of solar energy generation especially in inter-tropical sites is the local variability of clouds. Satellite images do not have temporal resolution enough to nowcast its impacts on solar plants, this monitoring is made by local cameras. However, cloud detection and monitoring are not trivial due to cloud shape dynamics, the camera is a linear and self-adjusting device, with fish-eye lenses generating a flat image that distorts images near the horizon. The present work focuses on cloud identification to predict its effects on solar plants that are distinct for every site’s climatology and geography. We used RASPBERY-PI-based cameras pointed at the horizon to allow observation of clouds’ vertical distribution, not possible with a unique fish-eye lens. A large number of cloud image identification analyses led the researchers to use deep learning methods such as U-net, HRnet, and Detectron. We use transfer learning with weights trained over the “2012 ILSVRC ImageNet” data set and architecture configurations like Resnet, Efficient, and Detectron2. While cloud identification proved a difficult task, we achieved the best results by using Jaccard Coefficient as a validation metric, with the best model being a U-net with Resnet18 using 486 × 648 resolution. This model had an average IoU of 0.6, indicating a satisfactory performance in cloud segmentation. We also observed that the data imbalance affected the overall performance of all models, with the tree class creating a favorable bias. The HRNet model, which works with different resolutions, showed promising results with a more refined segmentation at the pixel level, but it was not necessary to detect the most predominant clouds in the sky. We are currently working on balancing the dataset and mapping out data augmentation transformations for our next experiments. Our ultimate goal is to use such models to predict cloud motion and forecast the impact it will have on solar power generation. The present

关键词： Segmentation Cloud Nowcasting

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Interaction between Equatorial Plasma Bubbles and a Medium-Scale Traveling Ionospheric Disturbance,observed by OI 630 nm airglow imaging at Bom Jesus de Lapa,Brazil

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Earth and Planetary Physics 2021年第5期5卷 397-406页

作者： Cristiano Max Wrasse Cosme Alexandre Oliveira Barros Figueiredo Diego Barros Hisao Takahashi Alexander JoséCarrasco Luiz Fillip Rodrigues Vital Láysa Cristina Araujo Resende Fábio Egito Geângelo de Matos Rosa Antonio Hélder Rodrigues Sampaio space Weather Division National Institute for Space Research(INPE)São Josédos CamposBrazil University of Los Andes(ULA) MéridaVenezuela State Key Laboratory of space Weather Beijing 100190China Federal University of Campina Grande(UFCG) Campina GrandeBrazil Federal institute for Education Science and Technology Baiano(IF Baiano)Bom Jesus da LapaBrazil

OI 630.0 nm airglow observations,from a new observatory at Bom Jesus de Lapa,were used to study the interaction between EPBs(Equatorial Plasma Bubbles)and the MSTID(Medium-Scale Traveling Ionospheric Disturbance)over the Northeast region in *** the night of September 16 to 17,2020,an EPB was observed propagating eastward,in an apparent fossil stage,until it interacted with a dark band electrified MSTID(e MSTID).After the interaction,four EPBs merged,followed by an abrupt southward development and *** of the data suggests that an eastward polarization electric field,induced by the dark band e MSTID,forced the EPB into an upward drift,growing latitudinally along the magnetic field lines and then bifurcating.

关键词： Equatorial Plasma Bubbles Medium-Scale Traveling Ionospheric Disturbance ionosphere thermosphere EPB and MSTID interaction

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