Evaluation of a time dependent air pollution model with a new vertical turbulent parameterization

The paper presents the evaluation of a model, with a new vertical eddy exchange parameterization, based on a general technique for solving the K-equation, using the truncated Gram-Charlier expansion (type A) of the concentration field and a finite set equations for the corresponding moments. The model can be applied routinely using as input simple ground-level meteorological data acquired by an automatic network. A performance evaluation is shown in the case of continuous emission from an elevated source in a variable boundary layer

Aerosol Optical Depth of the Main Aerosol Species over Italian Cities Based on the NASA/MERRA-2 Model Reanalysis

The Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) provides data at 0.5° × 0.625° resolution covering a period from 1 January 1980 to the present. Natural and anthropogenic aerosols are simulated in MERRA-2, considering the Goddard chemistry, aerosol, radiation, and transport model. This model simulates the sources, sinks, and chemistry of mixed aerosol tracers: dust, sea salt, hydrophobic and hydrophilic black carbon and organic carbon, and sulfate. MERRA-2 aerosol reanalysis is a pioneering tool for investigating air quality issues, noteworthy for its global coverage and its distinction of aerosol speciation expressed in the form of aerosol optical depth (AOD). The aim of this work was to use the MERRA-2 reanalysis to study urban air pollution at a national scale by analyzing the AOD. AOD trends were evaluated for a 30-year period (1987–2017) over five Italian cities (Milan, Rome, Cagliari, Taranto, and Palermo) in order to investigate the impacts of urbanization, industrialization, air quality regulations, and regional transport on urban aerosol load. AOD evolution predicted by the MERRA-2 model in the period 2002–2017 showed a generalized decreasing trend over the selected cities. The anthropogenic signature on total AOD was between 50% and 80%, with the largest contribution deriving from sulfate

Estrutura da CLC em Áreas de Floresta e Pastagem na Amazônia usando Simulação de Grandes Vórtices

Some characteristics of the development of Convective BoundaryLayer (CBL) were studied for forest and pasture areas in Amazonia,using a large eddy simulation (LES) model. Observational data wereused for the initialization. The CBL was well simulated for both areas,with errors for its height above the pasture and above the forest of 1%and 5%, respectively.Some characteristics of the development of Convective BoundaryLayer (CBL) were studied for forest and pasture areas in Amazonia,using a large eddy simulation (LES) model. Observational data wereused for the initialization. The CBL was well simulated for both areas,with errors for its height above the pasture and above the forest of 1%and 5%, respectively

Air quality modelling system over a central mediterranean region

This work presents a complex modelling system for air quality studies. The system couples meteorological models, emission preprocessors and dispersion models. Two meteorological models have been coupled in cascade: a mesoscale meteorological model and a 3D diagnostic micro-meteorological model, which is able to provide a realistic three-dimensional wind and temperature fields and two dimensional fields of boundary layer parameters. The emission data were obtained trough disaggregation of national emission inventory, by using a database related to all industrial sources, and through direct evaluation of road transport and biogenic emissions. Meteorological fields and emission data have been used by a photochemical model and by a Lagrangian puff dispersion model. The modelling system has been applied over Salento Peninsula, located in the south-east corner of Italy, in the Mediterranean central area in a real typical summer scenario.Este trabalho apresenta um complexo sitema de modelagem para estudos de qualidade do ar, acoplando modelos meteorológicos, preprocessadores de emissão e modelos de dispersão. Dois modelos meteorológicos foram acoplados em cascata: um modelo meteorológico de mesoescala e um modelo de diagnóstico micrometorólgico 3-D; capaz de gerar campos realísticos e tridimensionais de vento e temperatura e campos bidimensionais de parâmetros da camada limite planetária. Os dados de emissão foram obtidos do inventário nacional de emissão, que consiste em um banco de dados de todas as fontes industriais, e por estimativa direta da emissão de veículos e biogênica. Os campos meteorológicos e dados de emissão foram inseridos em um modelo fotoquímico e um modelo de dispersão puff-Lagrangeano. Todo o sistema foi então aplicado na Península de Salento, localizada no extremo sudeste da Itália, área central do Mar Mediterrâneo, para um cenário típico de verão