Theory for expansion work applied to breezes of Northeast of Brazil

Neste artigo investiga-se numericamente a interação entre brisas marítima-terrestre e de vale-montanha, que ocorrem no nordeste brasileiro devido à presença do Planalto da Borborema, aplicando o trabalho de expansão associado ao ramo inferior das circulações. Resultados da teoria da máquina térmica são comparados aos resultados 3D, obtidos com a versão brasileira do modelo RAMS. Os resultados indicaram que o efeito do contraste de temperatura no trabalho ligado às circulações (Wa), isoladamente, contribui para a formação de brisas marítimas mais intensas e de brisas terrestres menos intensas. Na realidade, o que se observa são brisas terrestres com intensidades iguais ou até maiores que das brisas marítimas. Assim, a contribuição da montanha para a intensidade das circulações de brisa no período noturno mostra-se extremamente não-linear. O trabalho de expansão que realmente está ligado às circulações, contribui em apenas 7% para o trabalho total. Dessa forma, a maior parte do trabalho total está associada ao trabalho de compressão que a atmosfera realiza para compensar a perda por resfriamento radiativo, e muito da energia disponibilizada para as circulações é gasta para vencer os processos dissipativos.The purpose of this work is to further understand the interactions between sea-land breeze and valley-mountain breeze that occur at the coast of Northeast Brazil due to the presence of the Borborema plateau, using the associated expansion work at the lower branch of these circulations. Results of the thermal machine theory are compared to the 3D results obtained from the Brazilian RAMS model version. The results indicate that the sole effect of temperature contrast on the work associated with circulations (Wa) is more intense sea breezes and weaker land breezes. Actually, one can observe land breezes whose intensities are equal or even larger than sea breezes. Thus, the mountain contribution for the intensity of the breeze circulations in the nighttime is extremely non-linear. The expansion work that is actually associated with these circulations contributes only with 7% for the total work. Consequently, the larger part of the total work is associated with the compression work performed by the atmosphere in order to compensate long-wave cooling and much of the energy available for the circulations is consumed to overcome dissipation.CNP

CAPE and convective events in the southwest during the North American monsoon

The relationship between atmospheric stability, measured as CAPE, and deep precipitating convection has been widely studied but is not definitive. In the maritime tropics, CAPE and precipitation are usually inversely correlated. In continental convection (i.e., midlatitude and tropical), no consistent relationship has been found. In this study of the semiarid Southwest, a moderate positive correlation exists, approaching 0.6. Correlations based on radiosonde data are found to be sensitive to the parcel level of origin. The strongest correlations are found by modifying the preconvective morning sounding with the maximum reported surface temperature, assuming well-mixed adiabatic layers to the level of free convection with pseudoadiabatic ascent. These results show that the upper bounds on parcel instability correlate best with precipitation. Furthermore, the CAPE-precipitation relationship is argued to depend on the convective regime being considered. The North American monsoon convective regime requires essentially only moisture advection interacting with the strong surface sensible heating over complex topography. Elimination of strong convective inhibition through intense surface sensible heating in the presence of sufficient water vapor leads to the positive CAPE-precipitation relationship on diurnal time scales. These results are discussed in light of contradictory results from other continental and maritime regions, which demonstrate negative correlations. © 2009 American Meteorological Society

Testes com Esquemas de Parametrização de Convecção Profunda em um Evento Chuvoso Extremo

Este trabalho tem como objetivo através da simulação de umevento chuvoso extremo, comparar os esquemas de parametrizaçãoconvectiva. O modelo BRAMS foi usado para simular o período de 30de Julho de 2000 a 02 de Agosto de 2000. Dois experimentos foramrealizados utilizando os esquemas de parametrização de cúmulos de Kuoe Grell, com uma grade com 10 km de resolução horizontal. Concluiuseque o esquema de parametrização de convecção de Grell evidencioumelhor o evento obtendo resultados bastante satisfatórios

An analysis of rainfall based on entropy theory

The principle of maximum entropy can provide consistent basis for analyzing rainfall and for geophysical processes in general. The daily rainfall data was assessed using the Shannon entropy for a 10-years period from 189 stations in the northeastern region of Brazil. Mean values of marginal entropy were computed for all observation stations and isoentropy maps were then constructed for delineating annual and seasonal characteristics of rainfall. The Mann-Kendall test was used to evaluate the long-term trend in marginal entropy for two sample stations. The marginal entropy values of rainfall were higher for locations and periods with highest amount of rainfall. The results also showed that the marginal entropy decreased exponentially with increasing coefficient of variation. The Shannon theory produced spatial patterns which led to a better understanding of rainfall characteristics throughout the northeastern region of Brazil. Trend analysis indicated that most time series did not have any significant trends

Synoptic reorganization of atmospheric flow during the Last Glacial Maximum

A coupled global atmosphere–ocean model of intermediate complexity is used to study the influence of glacial boundary conditions on the atmospheric circulation during the Last Glacial Maximum in a systematical manner. A web of atmospheric interactions is disentangled, which involves changes in the meridional temperature gradient and an associated modulation of the atmospheric baroclinicity. This in turn drives anomalous transient eddy momentum fluxes that feed back onto the zonal mean circulation. Moreover, the modified transient activity (weakened in the North Pacific and strengthened in the North Atlantic) leads to a meridional reorganization of the atmospheric heat transport, thereby feeding back onto the meridional temperature structure. Furthermore, positive barotropic conversion and baroclinic production rates over the Laurentide ice sheets and the far eastern North Pacific have the tendency to decelerate the westerlies, thereby feeding back to the stationary wave changes triggered by orographic forcing

Inquérito sorológico da infecção por herpesvírus equino no Estado de Minas Gerais

Os herpesvírus equinos tipo 1 (HVE-1) e 4 (HVE-4) são agentes causadores de diferentes formas de doença em cavalos, das quais as mais comuns são a rinopneumonite, o abortamento, a mortalidade perinatal e a mieloencefalopatia herpética equinas, que causam grandes perdas econômicas. Tem sido descrita mundialmente, havendo poucos estudos no Brasil. O objetivo do presente trabalho foi estudar a ocorrência e a distribuição da infecção por herpesvírus equinos (HVE) em equídeos criados em dez Delegacias Regionais do Estado de Minas Gerais: Almenara, Bambuí, Curvelo, Governador Valadares, Montes Claros, Oliveira, São Gonçalo do Sapucaí, Teófilo Otoni, Unaí e Viçosa. Foi utilizada a técnica de soroneutralização em microplacas com o intuito de detectar anticorpos soro neutralizantes. Das amostras analisadas, 17,6% (145/826) foram soropositivas para o HVE, sendo 18,7% (140/749) cavalos soropositivos, 6,8% (5/73) muares soropositivos e nenhum asinino soropositivo (0/4). Conclui-se que o HVE-1 encontra-se amplamente disseminado no Estado de Minas Gerais, pois todas as regiões estudadas apresentaram animais sororreagentes ao HVE-1. Observou-se maior ocorrência de anticorpos contra o HVE em animais adultos, indicando assim o potencial desses animais como fonte de infecção para os potros.Equine herpesvirus type 1 (EHV-1) and 4 (EHV-4) are major pathogens affecting horses, and cause respiratory disease, abortion, perinatal mortality and neurological disease, bringing economical losses. This infection has been reported worldwide, but there are only a few studies in Brazil. The present study was undertaken in order to evaluate the occurrence and distribution of equine herpesviruses (EHV) infection in equids from ten regions of Minas Gerais State: Almenara, Bambuí, Curvelo, Governador Valadares, Montes Claros, Oliveira, São Gonçalo do Sapucaí, Teófilo Otoni, Unaí and Viçosa. To detect antibodies against EHV virus neutralization test in microplates was used. We found 17.6% (145/826) positive animals for EHV. 18.7% (140/749) positive horses, 6.8% (5/73) positive mules and none positive (0/4) donkeys. All ten regions studied showed animals reagents to EHV. The results suggest that EHV is widespread in equids of Minas Gerais State. It was observed a higher occurrence of antibodies against EHV in adult animals, indicating the potential of these animals as source of infection for foals

Assessing the Grell-Freitas Convection Parameterization in the NASA GEOS Modeling System

We implemented and began to evaluate an alternative convection parameterization for the NASA Goddard Earth Observing System (GEOS) general circulation model (GCM). The proposed parameterization follows the mass flux approach with several closures, for equilibrium and nonequilibrium convection, and includes scale and aerosol aware functionalities. Recently, we extended the scheme to a trimodal spectral size distribution of allowed convective plumes to simulate the transition among shallow, congestus, and deep convection regimes. In addition, the inclusion of a new closure for nonequilibrium convection resulted in a substantial gain of realism in the model representation of the diurnal cycle of convection over the land. We demonstrated the scaledependence functionality with a cascade of globalscale simulations from a nominal horizontal resolution of 50 km down to 6 km. The ability to realistically simulate the diurnal cycle of precipitation over various regions of the earth was verified against several remote sensingderived intradiurnal precipitation estimates. We extended the model performance evaluation for weatherscale applications by bringing together some available operational shortrange weather forecast models and global atmospheric reanalyses. Our results demonstrate that the GEOS GCM with the alternative convective parameterization has good properties and competitive skill in comparison with stateoftheart observations and numerical simulations

The Brazilian Developments on the Regional Atmospheric Modeling System (BRAMS 5.2): An Integrated Environmental Model Tuned for Tropical Areas

We present a new version of the Brazilian developments on the Regional Atmospheric Modeling System where different previous versions for weather, chemistry and carbon cycle were unified in a single integrated software system. The new version also has a new set of state-of-the-art physical parameterizations and greater computational parallel and memory usage efficiency. Together with the description of the main features are examples of the quality of the transport scheme for scalars, radiative fluxes on surface and model simulation of rainfall systems over South America in different spatial resolutions using a scale-aware convective parameterization. Besides, the simulation of the diurnal cycle of the convection and carbon dioxide concentration over the Amazon Basin, as well as carbon dioxide fluxes from biogenic processes over a large portion of South America are shown. Atmospheric chemistry examples present model performance in simulating near-surface carbon monoxide and ozone in Amazon Basin and Rio de Janeiro megacity. For tracer transport and dispersion, it is demonstrated the model capabilities to simulate the volcanic ash 3-d redistribution associated with the eruption of a Chilean volcano. Then, the gain of computational efficiency is described with some details. BRAMS has been applied for research and operational forecasting mainly in South America. Model results from the operational weather forecast of BRAMS on 5 km grid spacing in the Center for Weather Forecasting and Climate Studies, INPE/Brazil, since 2013 are used to quantify the model skill of near surface variables and rainfall. The scores show the reliability of BRAMS for the tropical and subtropical areas of South America. Requirements for keeping this modeling system competitive regarding on its functionalities and skills are discussed. At last, we highlight the relevant contribution of this work on the building up of a South American community of model developers

The Brazilian developments on the Regional Atmospheric Modeling System (BRAMS 5.2): an integrated environmental model tuned for tropical areas

We present a new version of the Brazilian developments on the Regional Atmospheric Modeling System (BRAMS), in which different previous versions for weather, chemistry, and carbon cycle were unified in a single integrated modeling system software. This new version also has a new set of state-of-the-art physical parameterizations and greater computational parallel and memory usage efficiency. The description of the main model features includes several examples illustrating the quality of the transport scheme for scalars, radiative fluxes on surface, and model simulation of rainfall systems over South America at different spatial resolutions using a scale aware convective parameterization. Additionally, the simulation of the diurnal cycle of the convection and carbon dioxide concentration over the Amazon Basin, as well as carbon dioxide fluxes from biogenic processes over a large portion of South America, are shown. Atmospheric chemistry examples show the model performance in simulating near-surface carbon monoxide and ozone in the Amazon Basin and the megacity of Rio de Janeiro. For tracer transport and dispersion, the model capabilities to simulate the volcanic ash 3-D redistribution associated with the eruption of a Chilean volcano are demonstrated. The gain of computational efficiency is described in some detail. BRAMS has been applied for research and operational forecasting mainly in South America. Model results from the operational weather forecast of BRAMS on 5 km grid spacing in the Center for Weather Forecasting and Climate Studies, INPE/Brazil, since 2013 are used to quantify the model skill of near-surface variables and rainfall. The scores show the reliability of BRAMS for the tropical and subtropical areas of South America. Requirements for keeping this modeling system competitive regarding both its functionalities and skills are discussed. Finally, we highlight the relevant contribution of this work to building a South American community of model developers.CNPqFAPESPEarth System Research Laboratory at the National Oceanic and Atmospheric Administration (ESRL/NOAA), Boulder, USAInst Nacl Pesquisas Espaciais, Ctr Previsao Tempo & Estudos Climat, Cachoeira Paulista, SP, BrazilDiv Ciência da Computação, Instituto Tecnológico de Aeronáutica, São José dos Campos, SP, BrazilUniv Estadual Paulista Unesp, Fac Ciencias, Bauru, SP, BrazilCtr Meteorol Bauru IPMet, Bauru, SP, BrazilUniv Fed Sao Paulo, Dept Ciencias Ambientais, Diadema, SP, BrazilUniv Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Sao Paulo, SP, BrazilUniv Fed Campina Grande, Dept Ciencias Atmosfer, Campina Grande, PB, BrazilEmbrapa Informat Agr, Campinas, SP, BrazilUniv Fed Sao Paulo, Inst Ciencia & Tecnol, Sao Jose Dos Campos, SP, BrazilUniv Fed Rio Grande do Norte, Dept Ciencias Atmosfer & Climat, Programa Pos Grad Ciencias Climat, Natal, RN, BrazilInst Nacl Pesquisas Espaciais, Ctr Ciencias Sistema, Sao Jose Dos Campos, SP, BrazilUniv Fed Sao Joao Del Rei, Dept Geociencias, Sao Joao Del Rei, MG, BrazilInst Nacl Pesquisas Espaciais, Lab Associado Computacao & Matemat Aplica, Sao Jose Dos Campos, BrazilUniv Evora, Inst Ciencias Agr & Ambientais Mediterr, Evora, PortugalUniv Lusofona Humanidades & Tecnol, Ctr Interdisciplinar Desenvolvimento Ambient Gest, Lisbon, PortugalUniv Fed Pelotas, Fac Meteorol, Pelotas, RS, BrazilUnive Tecnol Fed Parana, Londrina, PR, BrazilNASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Goddard Earth Sci Technol & Res Global Modeling &, Greenbelt, MD USAUniv Fed Sao Paulo, Inst Ciencia & Tecnol, Sao Jose Dos Campos, SP, BrazilUniv Fed Sao Paulo, Inst Ciencia & Tecnol, Sao Jose Dos Campos, SP, BrazilCNPq: 306340/2011-9FAPESP: 2014/01563-1FAPESP: 2015/10206-0FAPESP: 2014/01564-8Web of Scienc