Artigos - Instituto de Pesquisas Meteorológicas (IPMet) - Bauru

URI Permanente para esta coleção

https://hdl.handle.net/11449/25227

Navegar

Agora exibindo 1 - 20 de 117

Characterization and evaluation of antioxidant and antimicrobial capacity of prepared liquid smoke-loaded chitosan nanoparticles
(2022-04-01) Tuesta-Chavez, Tarsila; Monteza, José; Silva Jaimes, Marcial I.; Ruiz-Pacco, Gustavo A.; Changanaqui, Katherina; Espinoza – Suarez, José B.; Alarcon, Hugo; Osorio – Anaya, Ana M.; Valderrama – Negrón, A. C.; Sotomayor, Maria D.P.T. [UNESP]; Chemical Engineering - National University of Engineering (GIA-FIQT-UNI); National Agrarian University; Universidad Nacional Mayor de San Marcos; National University of Engineering; Universidade Estadual Paulista (UNESP); Toxicological Evaluation & Removal of Micropollutants and Radioactives (INCT-DATREM)
The combined application of chitosan (CS) and liquid smoke (LS) leads to the development of a suitable material with synergistic properties and promising potential for use as an efficient preservative for the conservation of food products. The present work investigates the development and characterization of liquid smoke-loaded chitosan nanoparticles (LS-CS/NPs) with the optimization of the preparation conditions using response surface methodology and the analysis of the antioxidant and antibacterial properties of the nanoparticles as well as the controlled release of the liquid smoke. The nanoparticles were prepared by the ionic gelation method and were characterized by DLS, zeta potential, FT-IR, SEM, and EDS. The analysis of antioxidant activity of LS-CS/NPs was performed by the free radicals scavenging method (DPPH and ABTS) while the study of the total phenolic content of the particles was conducted via the application of the Folin-Ciocalteau method with some modifications. The analysis of antimicrobial activity of the LS-CS/NPs was performed using the minimum inhibitory concentration method involving the growth of Gram-positive (S. aureus and B. cereus) and Gram-negative (E. coli and Salmonella spp) bacteria. The analysis of the controlled release of liquid smoke was conducted at 4 °C using the Korsmeyer-Peppas model. The results obtained showed that the nanoparticles prepared using CS and LS in the ratio 1.5: 0.583, respectively (F′2), which had an average size of 205 nm and zeta potential of 45 mV, exhibited good antioxidant (%DPPH: 92.7% and %ABTS: 93%) and antibacterial activities, with an efficient, gradual controlled release of liquid smoke (release rate = 0.042 min−1).
Contrasting convective regimes over the Amazon: Implications for cloud electrification
(2002-01-01) Williams, E.; Rosenfeld, D.; Madden, N.; Gerlach, J.; Gears, N.; Atkinson, L.; Dunnemann, N.; Frostrom, G.; Antonio, M.; Biazon, B.; Camargo, R.; Franca, H.; Gomes, A.; Lima, M.; Machado, R.; Manhaes, S.; Nachtigall, L.; Piva, H.; Quintiliano, W.; Machado, L.; Artaxo, P.; Roberts, G.; Renno, N.; Blakeslee, R.; Bailey, J.; Boccippio, D.; Betts, A.; Wolff, D.; Roy, B.; Halverson, J.; Rickenbach, T.; Fuentes, J.; Avelino, E.; Massachusetts Institute of Technology; Hebrew University; NASA Wallops Island Flight Facility; IPMET; Centro Tecnico Aeroespacial; Universidade de São Paulo (USP); Max Planck Institute for Chemistry; University of Arizona; NASA Marshall Space Flight Center; Atmospheric Research; NASA Goddard Space Flight Center; University of Virginia; Embratel; Instituto de Pesquisas Meterologicas; Instituto de Fisica; Atmospherica Research; NASA/MSFC; Divisao de Ciencias Atmosfericas; Scripps Institue of Oceanography; Parsons Laboratory
Four distinct meteorological regimes in the Amazon basin have been examined to distinguish the contributions from boundary layer aerosol and convective available potential energy (CAPE) to continental cloud structure and electrification. The lack of distinction in the electrical parameters (peak flash rate, lightning yield per unit rainfall) between aerosol-rich October and aerosol-poor November in the premonsoon regime casts doubt on a primary role for the aerosol in enhancing cloud electrification. Evidence for a substantial role for the aerosol in suppressing warm rain coalescence is identified in the most highly polluted period in early October. The electrical activity in this stage is qualitatively peculiar. During the easterly and westerly wind regimes of the wet season, the lightning yield per unit of rainfall is positively correlated with the aerosol concentration, but the electrical parameters are also correlated with CAPE, with a similar degree of scatter. Here cause and effect are difficult to establish with available observations. This ambiguity extends to the ‘‘green ocean’’ westerly regime, a distinctly maritime regime over a major continent with minimum aerosol concentration, minimum CAPE, and little if any lightning.
Automatic methods to detect the top of atmospheric boundary layer
(2013-12-23) De A. Moreira, Gregori; Bourayou, Riad; Da Silva Lopes, Fábio J.; Albuquerque, Taciana A.; Reis, Neyval C.; Held, Gerhard; Landulfo, Eduardo; Cidade Universitária; Federal University of Espírito Santo; Universidade de São Paulo (USP)
The main objective of this work is to obtain methods that automatically allow qualitative detections of Atmospheric Boundary Layer heights from LIDAR data. Case studies will be used to describe the more relevant days of a campaign carried out in July of 2012 in Vitória, Espírito Santo, Brazil. The data analysis compares three mathematical algorithms that automatically provide the ABL height: Gradient Method (GM), using the derivative of the Range Corrected Signal (RCS) logarithm, WCT (Wavelet Covariance Transform), and Bulk Richardson's Number, which was used to validate the methods mentioned above. The comparison between the methods has shown that as the presence of clouds and the aerosol sublayer increased, the more sensitive was the refinement needed to choose the right parameters, whereas even Richardson's method had ambiguities in finding a good estimate of the ABL top. © 2013 SPIE.
The humidity sounder for Brazil: an international partnership
(2003-02) Lambrigtsen, Bjorn H.; Calheiros, Roberto V.; California Institute of Technology; Brazilian National Institute for Space Research; University of the State of São Paulo
The Humidity Sounder for Brazil (HSB) is a crucial component of the Atmospheric Infrared Sounder (AIRS) sounding suite and a valuable contribution from Brazil to the National Aeronautics and Space Administration's Aqua mission. Its design and functionality are practically identical to that of the Advanced Microwave Sounding Unit-B - proven on the latest National Oceanic and Atmospheric Administration's weather satellites. We briefly discuss its heritage, the measurement concept and principle of operation, and the design. The complex multinational acquisition process employed for HSB is described, along with the approach to be used for operations, derivation of radiometric and geophysical data products, and validation of those products-with emphasis on activities in Brazil. We also describe postlaunch research plans and discuss the importance of humidity observations in tropical regions like Brazil. © 2003 IEEE.
Climatologia de frentes frias no litoral de Santa Catarina
(Sociedade Brasileira de Geofísica, 2004-08) Rodrigues, Maria Laura Guimarães; Franco, Davide; Sugahara, Shigetoshi [UNESP]; Secretaria de Estado do Desenvolvimento Rural e da Agricultura - SC; Universidade Federal de Santa Catarina (UFSC); Universidade Estadual Paulista (Unesp)
Uma climatologia de frentes frias é estabelecida para o litoral do Estado de Santa Catarina, com base nos dados de reanálises do NCEP-NCAR, do período de 10 anos, de 1990 a 1999. As passagens de frentes frias foram objetivamente identificadas levando em conta o giro do vento para direção sul, persistência do vento de sul por pelo menos um dia, e uma queda de temperatura do ar simultânea ao giro do vento ou até dois dias depois. Os resultados mostram que, na média, de 3 a 4 frentes frias atingem a costa de Santa Catarina, mensalmente, com um intervalo de 8 dias. As análises da composição de dados, usando como referência os dias de passagens de frentes frias em Santa Catarina, mostram claramente um padrão climatológico de evolução com frente fria movendo-se tipicamente de sudoeste para nordeste. em termos das médias sazonais, durante o inverno, um dia antes da passagem em Santa Catarina (dia -1), a frente fria é observada no Rio Grande do Sul, e depois de passar por Santa Catarina (dia 0), continua avançando para latitudes mais baixas, alcançando o litoral do Rio de Janeiro um dia depois (dia +1), até atingir posteriormente latitude de aproximadamente 20ºS (dia +2), já em fase de dissipação. No terceiro dia após a passagem por Santa Catarina, ela não é mais identificada. Padrão climatológico de evolução semelhante é observado no verão, embora nessa época as frentes frias tenham menor intensidade e dissipação ligeiramente mais rápida.
Early and geophysical validation of METOP / IASI water vapour measurements in the tropical upper troposphere and lower stratosphere, PI 3051
(2006-08-01) Pommereau, J. P.; Durry, G.; Hauchecorne, A.; Held, G.; Calheiros, R. V.; Yushkov, V.; CNRS Service d'Aéronomie; Universidade de São Paulo (USP); Central Aerological Observatory
The proposal is dedicated to the validation of METOP / IASI water vapour measurements in the tropical tropopause layer where air enters the stratosphere by still debated processes and for the study of which very little reliable data exist. The initial proposal split in three parts: i) the comparison of IASI measurements to balloon, sondes and high altitude aircraft measurements in July-August 2006 in West Africa during a SCOUT-AMMA campaign part of the SCOUT-O3 Integrated Project of the European Commission; ii) the comparison of a large number of water vapour profiles in the 5-25 km altitude range anticipated from circumnavigating long duration balloons during a further SCOUT-Equatorial campaign in autumn 2007 in Brazil, and iii) a statistical comparison with year round water vapour soundings in Brazil using the Russian FLASH Lyman alpha instrument operated by the IPMet in Bauru, Brazil. After thorough validation the proposal is to use the IASI data for exploring the seasonal and inter-annual variations of water vapour concentration in the TTL.
Intercontinental transport of nitrogen oxide pollution plumes
(2003-01-01) Wenig, M.; Spichtinger, N.; Stohl, A.; Held, G.; Beirle, S.; Wagner, T.; Jähne, B.; Platt, U.; Heidelberg University; Interdisziplinäres Zentrum für Wissenschaftliches Rechnen; TUM; Universidade Estadual; NASA Goddard Space Flight Center
We describe the first satellite observation of intercontinental transport of nitrogen oxides emitted by power plants, verified by simulations with a particle tracer model. The analysis of such episodes shows that anthropogenic NOx plumes may influence the atmospheric chemistry thousands of kilometers away from its origin, as well as the ocean they traverse due to nitrogen fertilization. This kind of monitoring became possible by applying an improved algorithm to extract the tropospheric fraction of NO2 from the spectral data coming from the GOME instrument. As an example we show the observation of NO2 in the time period 4-14 May, 1998, from the South African Plateau to Australia which was possible due to favourable weather conditions during that time period which availed the satellite measurement. This episode was also simulated with the Lagrangian particle dispersion model FLEXPART which uses NOx emissions taken from an inventory for industrial emissions in South Africa and is driven with analyses from the European Centre for Medium-Range Weather Forecasts. Additionally lightning emissions were taken into account by utilizing Lightning Imaging Sensor data. Lightning was found to contribute probably not more than 25% of the resulting concentrations. Both, the measured and simulated emission plume show matching patterns while traversing the Indian Ocean to Australia and show great resemblance to the aerosol and CO2 transport observed by Piketh et al. (2000). © European Geosciences Union 2003.
On the cross-tropopause transport of water by tropical convective overshoots: A mesoscale modelling study constrained by in situ observations during the TRO-Pico field campaign in Brazil
(2022-01-19) Behera, Abhinna K.; Rivière, Emmanuel D.; Khaykin, Sergey M.; Marécal, Virginie; Ghysels, Mélanie; Burgalat, Jérémie; Held, Gerhard [UNESP]; UFR Sciences Exactes et Naturelles; CNRS; Universidade Estadual Paulista (UNESP); UMR 8518 - LOA - Laboratoire d'Optique Atmosphérique
Deep convection overshooting the lowermost stratosphere is well known for its role in the local stratospheric water vapour (WV) budget. While it is seldom the case, local enhancement of WV associated with stratospheric overshoots is often published. Nevertheless, one debatable topic persists regarding the global impact of this event with respect to the temperature-driven dehydration of air parcels entering the stratosphere. As a first step, it is critical to quantify their role at a cloud-resolving scale before assessing their impact on a large scale in a climate model. It would lead to a nudging scheme for large-scale simulation of overshoots. This paper reports on the local enhancements of WV linked to stratospheric overshoots, observed during the TRO-Pico campaign conducted in March 2012 in Bauru, Brazil, using the BRAMS (Brazilian version of the Regional Atmospheric Modeling System; RAMS) mesoscale model. Since numerical simulations depend on the choice of several preferred parameters, each having its uncertainties, we vary the microphysics or the vertical resolution while simulating the overshoots. Thus, we produce a set of simulations illustrating the possible variations in representing the stratospheric overshoots. To better resolve the stratospheric hydration, we opt for simulations with the 800gm horizontal-grid-point presentation. Next, we validate these simulations against the Bauru S-band radar echo tops and the TRO-Pico balloon-borne observations of WV and particles. Two of the three simulations' setups yield results compatible with the TRO-Pico observations. From these two simulations, we determine approximately 333-2000gt of WV mass prevailing in the stratosphere due to an overshooting plume depending on the simulation setup. About 70g% of the ice mass remains between the 380 and 385gK isentropic levels. The overshooting top comprises pristine ice and snow, while aggregates only play a role just above the tropopause. Interestingly, the horizontal cross section of the overshooting top is about 450gkm2 at the 380gK isentrope, which is similar to the horizontal-grid-point resolution of a simulation that cannot compute overshoots explicitly. In a large-scale simulation, these findings could provide guidance for a nudging scheme of overshooting hydration or dehydration.
Future climate trends of subtropical cyclones in the South Atlantic basin in an ensemble of global and regional projections
(2022-02-01) de Jesus, Eduardo Marcos; da Rocha, Rosmeri Porfírio; Crespo, Natália Machado; Reboita, Michelle Simões; Gozzo, Luiz Felippe [UNESP]; Universidade de São Paulo (USP); Universidade Federal de Itajubá; Universidade Estadual Paulista (UNESP)
The South Atlantic Ocean (SAO) is characterized by the development of different types of synoptic scale cyclones, which affect the weather and climate of South America. For the first time, we obtained the long term trend of subtropical cyclones (SCs) climatology over the SAO through two ensembles under RCP8.5 scenario. Regional Climate Model version 4 (RegCM4) projections were driven by three global climate models (GCMs) from CMIP5. SCs are obtained by applying three algorithms: (1) for tracking all cyclones based on relative vorticity; (2) to describe the thermal structure of the cyclones; and (3) for selecting only the SCs. Ensemble means are able to capture the main SCs characteristics shown by ERA-Interim reanalysis in the present climate (1979–2005), such as the main region of formation (near the southeastern Brazilian coast), track density, seasonality (higher frequency in austral summer) and lifetime (~ 3 days). The RegCM4 and GCMs ensembles project a negative and statistically significant trend in the frequency of SCs in the future climate (2050–2080) near the southeastern coast of Brazil. The projections also indicate a greater negative trend of SCs than for all cyclones. This would be a response to the future increase in the mean sea level pressure (expansion of South Atlantic subtropical anticyclone), which in turn leads to a change in the low-level circulation acting to decrease the moisture transport to the main region of SCs development. Though the SCs frequency will decrease in the future, they are projected to be more intense due to stronger convective forcing.
Global exposure of population and land-use to meteorological droughts under different Warming Levels and Shared Socioeconomic Pathways: A Coordinated Regional Climate Downscaling Experiment-based study
(2021-01-01) Spinoni, Jonathan; Barbosa, Paulo; Bucchignani, Edoardo; Cassano, John; Cavazos, Tereza; Cescatti, Alessandro; Christensen, Jens Hesselbjerg; Christensen, Ole Bøssing; Coppola, Erika; Evans, Jason; Forzieri, Giovanni; Geyer, Beate; Giorgi, Filippo; Jacob, Daniela; Katzfey, Jack; Koenigk, Torben; Laprise, René; Lennard, Christopher John; Levent Kurnaz, M.; Li, Delei; Llopart, Marta [UNESP]; McCormick, Niall; Naumann, Gustavo; Nikulin, Grigory; Ozturk, Tugba; Panitz, Hans-Jürgen; da Rocha, Rosmeri Porfirio; Solman, Silvina Alicia; Syktus, Jozef; Tangang, Fredolin; Teichmann, Claas; Vautard, Robert; Vogt, Jürgen Valentin; Winger, Katja; Zittis, George; Dosio, Alessandro; Joint Research Centre (JRC); Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC Foundation—REMHI Division); University of Colorado; Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE); Niels Bohr Institute (NBI); Danish Meteorological Institute; Abdus Salam International Centre for Theoretical Physics (ICTP); University of New South Wales; Institute of Coastal Research; Climate and Atmosphere Research Center (CARE-C); Helmholtz-Zentrum Geesthacht; Commonwealth Scientific and Industrial Research Organisation (CSIRO) Marine and Atmospheric Research; Rossby Centre; Université du Quebec à Montréal (UQAM); Climate System Analysis Group (CSAG); Bogazici University; Chinese Academy of Sciences (CAS); Universidade Estadual Paulista (UNESP); Isik University; Karlsruhe Institute of Technology (KIT); Universidade de São Paulo (USP); Universidad de Buenos Aires; Centro de Investigaciones del Mar y la Atmósfera (CIMA/CONICET-UBA); The University of Queensland; The National University of Malaysia (UKM); Laboratoire des Sciences du Climat et de l'Environnement (LSCE); Norwegian Research Centre AS; Centro Italiano Ricerche Aerospaziali (CIRA)
Global warming is likely to cause a progressive drought increase in some regions, but how population and natural resources will be affected is still underexplored. This study focuses on global population and land-use (forests, croplands, pastures) exposure to meteorological drought hazard in the 21st century, expressed as frequency and severity of drought events. As input, we use a large ensemble of climate simulations from the Coordinated Regional Climate Downscaling Experiment, population projections from the NASA-SEDAC dataset, and land-use projections from the Land-Use Harmonization 2 project for 1981–2100. The exposure to drought hazard is presented for five SSPs (SSP1-SSP5) at four Global Warming Levels (GWLs, from 1.5 to 4°C). Results show that considering only Standardized Precipitation Index (SPI; based on precipitation), the combination SSP3-GWL4 projects the largest fraction of the global population (14%) to experience an increase in drought frequency and severity (vs. 1981–2010), with this value increasing to 60% if temperature is considered (indirectly included in the Standardized Precipitation-Evapotranspiration Index, SPEI). With SPEI, considering the highest GWL for each SSP, 8 (for SSP2, SSP4, and SSP5) and 11 (SSP3) billion people, that is, more than 90%, will be affected by at least one unprecedented drought. For SSP5 (fossil-fuelled development) at GWL 4°C, approximately 2·106 km2 of forests and croplands (respectively, 6 and 11%) and 1.5·106 km2 of pastures (19%) will be exposed to increased drought frequency and severity according to SPI, but for SPEI, this extent will rise to 17·106 km2 of forests (49%), 6·106 km2 of pastures (78%), and 12·106 km2 of croplands (67%), with mid-latitudes being the most affected areas. The projected likely increase of drought frequency and severity significantly increases population and land-use exposure to drought, even at low GWLs, thus extensive mitigation and adaptation efforts are needed to avoid the most severe impacts of climate change.
Performance of the coupling RegCM4.3 and CLM3.5: An analysis over southeastern Brazil
(2018-01-01) Llopart, Marta Pereira [UNESP]; Reboita, Michelle Simões [UNESP]; Rocha, Rosmeri Porfírio da [UNESP]; Machado, Jeferson Prietsch [UNESP]; Universidade Estadual Paulista (UNESP)
This work analyzed the 3.5 land surface scheme coupled in the Regional Climate Model RegCM4 (RegCLM), seeking to identify the impact of this coupling in the climatology and in the interannual variability, mainly in the Southeast of Brazil. The climatology analysis showed that the RegCLM, for DJF, is more humid than the set of observations used, overestimating the South Atlantic Convergence Zone (SACZ) due to the RegCLM simulate more intense the northeast trade winds, and with this, there is a transportation of moisture from the Tropical Atlantic Ocean to the continent trhought the Low Level Jet (LLJ), intensifying the SACZ. For air temperature, RegCLM is colder than observations in the SDE region. This result also occurs in the analysis of the annual cycle and, especially in winter, reaching the difference of 1.8oC. During summer, lowest simulation errors were found for this variable. For the interannual variability for the SDE, the simulated precipitation presents an intensify pattern of the signal and reverse the phase of the observed anomaly. For air temperature, the simulation agrees with the observations, intensifying in some years the anomalies.
Impact of Z-R relationship on flow estimates in central São Paulo
(2012-12-01) Calheiros, Roberto V. [UNESP]; Gomes, Ana M. [UNESP]; Universidade Estadual Paulista (UNESP)
Mean areal radar rainfall over catchments in the State of São Paulo is an operational product under development by the Meteorological Research Institute - IPMet. A pilot project is being carried out which focuses on the important Corumbatai River basin, under surveillance by the IPMet-operated Bauru radar. Previous work on the project explored the relative impact of factors like time resolution of radar data and reflectivity to rain-rate conversion relationships, when the relevance of the latter was verified. This paper deals with the stratification of those relationships by daily intervals and its impact on flow estimates. Daily values of radar mean rainfall using gauges and different conversion relationships are plotted against the corresponding flow at the basin outlet. Flow estimates derived by applying the rainfall from the different relationships to a previously obtained rainfall-runoff curve for the basin is compared to the historical hydrograph. Preliminary results suggest stratification has hydrological significance. Copyright © 2012 IAHS Press.
Crossover between macroscopic and mesoscopic regimes of vortex interactions in type-II superconductors
(2012-06-11) Zadorosny, Rafael [UNESP]; Sardella, Edson [UNESP]; Malvezzi, André Luiz [UNESP]; Lisboa-Filho, Paulo Noronha [UNESP]; Ortiz, Wilson Aires; Universidade Estadual Paulista (UNESP); Universidade Federal de São Carlos (UFSCar); Norwegian Academy of Science and Letters
In the present work we report the existence of a crossover between the macroscopic and mesoscopic regimes of vortex interactions in type-II superconductors. Our findings rely on a systematic procedure to determine this crossover, which is based on the influence of the surface on the vortex structure of small superconductors. An adjacent result that we have found is that near this regime transformation, the vortex lattice develops a progressive change of symmetry, from square to hexagonal, which is intimately related to the meso-to-macro crossover. Our numerical simulations have been done for a long superconducting cylinder of square cross section for a wide range of length scales and temperatures. © 2012 American Physical Society.
Estimación de la heredabilidad del intervalo de partos en bovinos cruzados
(2008-01-01) Oscar Vergara, G.; Mario Cerón, M.; Naudin Hurtado, L. [UNESP]; Elkin Arboleda, Z.; Juan Granada, P.; Clara Rúa, B.; Grupo de Genética y Mejoramiento Animal; Facultad de Medicina Veterinaria y Zootecnia; Universidade Estadual Paulista (UNESP)
Objetive: To estimate the heritability of interval calving in crossbred cattle. Materials and methods: Information from database of La Leyenda farm, in the municipality of Caucasia (Antioquia) was used. A single-trait animal model was used, that included genetic group, year of birth, season of birth and the number of calvings as fixed effects and the additive direct genetic, permanent environmental and residual as random effects. Results: The heritability estimated was 0.15 ± 0.07 and the phenotypic mean was 544 ± 97 days. Conclusions: The heritability for the interval between calvings was low, indicating that little genetic progress can be achieved by selecting for this characteristic.
Estimativa da irradiação total sobre uma superfície inclinada a partir da irradiação global na horizontal
(2003-08-01) Scolar, José [UNESP]; Martins, Dinival [UNESP]; Escobedo, João Francisco [UNESP]; Universidade Estadual Paulista (UNESP)
A modeling study of the total irradiation reaching a tilted surface facing towards the Equator at a place with the same latitude (-22.85°), using the Daily partitioning energy, is presented. In this study three total irradiation incident on tilled surface estimate models (LIU; JORDAN, 1963; HAY, 1979; PEREZ et al., 1987) were modified in two different manners, to improve irradiation estimative model for tilted surface knowing only the global irradiation. The first modification consisted to apply empirical functions to determine the diffuse irradiation by the global radiation measurements. These empirical functions were tuned using a linear regression technique, the fraction of the diffuse irradiation (Kd) from the global irradiation, was correlated with the clearness index (Kd). In this case the highest correlation found was a fourth order polynomial function. In the second modification the fraction of the direct irradiation KBH from the global irradiation was correlated assuming a linear correlation at given intervals of K t. Model results showed that the empirical relationship K BH=f(Kt) presented better results and the Hay model presented a better performance compared with the two others models for the Botucatu region.
Uma experiência com modelo estatístico (MOS) para a previsão da temperatura mínima diária do ar
(2000-03-01) Sugahara, S. [UNESP]; Universidade Estadual Paulista (UNESP)
A MOS (Model Output Statistics) multiple regression equation for the prediction of daily minimum air temperature at the city of Bauru, in São Paulo State, is developed. The multiple regression equation, obtained using stepwise regression analysis, has four predictors, three from the CPTEC (Centre of Weather Forecast and Climate Studies) global model and one from observational data of the meteorological station at IPMet (Institute of Meteorological Research), Bauru. The predictors are the model 24 hours prognosis, valid at 00:00GMT, of 1000hPa temperature, 850hPa meridional wind and 1000hPa relative humidity, and the 18:00GMT observation of temperature. These four predictors account for approximately 80 percent of the total variance of the predictand, with a root mean square error of 1.4°C, i.e., approximately half of the standard deviation of daily mininum temperature observed at the IPMet station. A verification of the MOS equation with an independent sample of 47 cases shows that the forecast value is not significantly deteriorated when the observational predictor is not considered. The MOS equation, with or without this predictor, produces forecast with absolute errors smaller than 7.5°C in 70 percent of the cases studied. This result encourages the use of the MOS technique for operational daily minimum air temperature forecasting and the development of this technique for other weather elements and other localities.
Numerical simulation of the planetary boundary layer in Iperó, SP-Brazil
(2000-01-01) Scolar, J. [UNESP]; Neto, E. S.C. [UNESP]; De Oliveira, A. P.; Soares, J.; Universidade Estadual Paulista (UNESP); Universidade de São Paulo (USP)
One-dimensional second order numerical model coupled with surface budget energy prognostic equations is used to simulate the planetary boundary layer (PBL) in the region of Iperó-SP. Model results indicate that vertical turbulent sensible and latent heat fluxes decrease upwards quasi-linearly from a maximum positive value at the surface. This implies that heat and humidity are transported from the ground surface into the higher atmosphere. The mechanical turbulent flux at night is very small and the thermal flux nearly ceases in all PBL vertical extension. Consequently, temperature and humidity mean vertical profiles are better simulated during the daylight period. On the other hand, the surface fluxes and simulated radiation budget are in very good agreement with the observed values. Therefore, the inclusion of the surface energy budget equation permits a significant improvement on the air near surface daily cycle temperature simulation.
Regional circulation differences between a rainy episode and a nonrainy episode in eastern São Paulo State in March 2006
(Sociedade Brasileira de Meteorologia, 2008-12) Satyamurty, Prakki; Sousa Jr, Serafim Barbosa De; Teixeira, Mateus Da Silva [UNESP]; Silva, Lucia Eliane Maria Gularte Da; Instituto Nacional de Pesquisas da Amazônia; Instituto Nacional de Pesquisas Espaciais; Universidade Estadual Paulista (Unesp); Instituto Nacional de Meteorologia
The differences between the regional flow characteristics of a rainy episode and a nonrainy episode in March 2006 in eastern São Paulo state are discussed. The surface humidity and temperature characteristics do not show significant differences between the two cases. The composites of the middle tropospheric geopotential field and the lower-tropospheric wind field show a short-wave trough in the Atlantic off southern Brazil during the rainy episode. In the upper troposphere, the Bolivian high is stronger during the rainy episode than during the nonrainy episode, indicating that the troposphere over tropical South America is warmer during the rainy episode. The low-level jet in the rainy case does not penetrate northern Argentina, and is more NW-SE oriented, indicating that the humidity transport is more toward the southeastern Brazil. The moisture flux convergence over the eastern São Paulo at the 850-hPa is fairly strong in the rainy case whereas it is divergent in the nonrainy case. The presence of a low pressure area in the South Atlantic with westward tilt in the vertical provides synoptic forcing for the rising motion over eastern São Paulo state. These differences seem to be useful indicators for distinguishing rainy and nonrainy episodes.
Multi-model climate projections of the main cyclogenesis hot-spots and associated winds over the eastern coast of South America
(2021-01-01) de Jesus, Eduardo Marcos; da Rocha, Rosmeri Porfírio; Crespo, Natália Machado; Reboita, Michelle Simões; Gozzo, Luiz Felippe [UNESP]; Universidade de São Paulo (USP); Universidade Federal de Itajubá; Universidade Estadual Paulista (Unesp)
In this study, multi-model ensembles are used to understand regional features of future climate trends of cyclones and associated winds in eastern South America. For this, we consider three cyclogenetic hot-spot regions located in south-southeastern Brazil, extreme southern Brazil-Uruguay, and southern Argentina, named, respectively, RG1, RG2 and RG3. The multi-model ensembles consist of four RegCM4 downscalings (RegCM4s) nested in three different global circulation models (GCMs) from CMIP5 under RCP8.5 for the period 1979–2100. ERA-Interim, and CFSR provide the reanalyses ensemble. For the present climate (1979–2005), RegCM4s and GCMs simulate the main characteristics of the cyclone’s genesis and propagation. There is greater agreement between RegCM4s and reanalyses regarding the magnitude and location of stronger winds associated with intense cyclones starting in RG1 and RG2. An important added value is the greater ability of RegCM4s to capture the observed features (phase and amplitude of the annual cycle, intensity, and near surface winds) of cyclogenesis starting in regions away from the boundary domain, such as in RG1 and RG2. In these regions, RegCM4s present smaller (higher) error (correlation) for the frequency of cyclones than GCMs, which improves the representation of cyclones for the whole southwestern South Atlantic domain. RegCM4s are able to simulate in greater agreement with reanalysis than GCMs, the initially stronger cyclones and associated low level winds. For these intense cyclones in the future climate, an intensification of low-level winds off the coast (south-southeast Brazil and south Argentina) and a shift to the south of the upper-level polar jet are projected. Furthermore, there is a clear trend towards decrease in the number of cyclogeneses in each hot-spot region, indicating that each intense cyclone will be associated with stronger low level winds near the eastern South America coast at the end of the twenty-first century.
Future changes in the wintertime cyclonic activity over the CORDEX-CORE southern hemisphere domains in a multi-model approach
(2020-01-01) Reboita, Michelle Simões; Reale, Marco; da Rocha, Rosmeri P.; Giorgi, Filippo; Giuliani, Graziano; Coppola, Erika; Nino, Rosa Beatriz Luna; Llopart, Marta [UNESP]; Torres, Jose Abraham; Cavazos, Tereza; UNIFEI; The Abdus Salam International Centre for Theoretical Physiscs; Istituto Nazionale di Oceanografia e Geofisica Sperimentale OGS; Universidade de São Paulo (USP); CICESE; Universidade Estadual Paulista (Unesp); IPMet
Changes in the characteristics of austral winter (June–July–August) synoptic activity in three domains (Africa, Australia and South America) of the extratropical Southern Hemisphere projected with the Regional Climate Model version 4 (RegCM4) are presented. The model is nested in three global climate models (GCMs) from the Coupled Model Intercomparison Project phase 5 (CMIP5) under the Representative Concentration Pathway 8.5. The model grid spacing is 25 km and the simulations cover the period 1970–2100. Synoptic activity is analyzed using both Eulerian and Lagrangian approaches. The Eulerian analysis shows an increase of the synoptic activity south of 40° S in the RegCM4 and GCMs ensembles for the future (2080–2099) compared to the present (1995–2014), but this signal does not necessarily indicate an increase in the cyclone frequency since it includes cyclonic and anticyclonic features. The Lagrangian analysis, however, indicates a decrease in the frequency of cyclones, with a positive tendency towards stronger systems, although the latter is not statistically significant at 95% confidence level. Lifetime, traveled distance and mean speed of the cyclones do not present statistically significant changes in the future climate. On the other hand, a significant increase in both intensity and extension of areas affected by precipitation associated with cyclones is found. As a consequence, there is a statistically significant trend of individual cyclones to produce more rainfall in the future.

Navegar

Submissões Recentes