The CHIMERE v2020r1 online chemistry-transport model

TL;DR: A deep spatiotemporal model based on a 2D convolutional neural network and a long short-term memory network for predicting air pollution provides good and consistent prediction results and demonstrates the benefits of including spatial information from as many surrounding stations as possible, as well as using as much historical information as possible.

TL;DR: In this article , the atypical huge forest fires observed in France during the summer of 2022 are modeled using the CHIMERE model and the impact of these emissions is quantified on ozone, aerosols and aerosol optical depth.

TL;DR: In this article , four air quality modelling systems, based on three chemical transport models (CHIMERE, FARM and CAMx) were applied over the Po Valley to assess the sensitivity of PM2.5 concentrations to NOx and NH3 emission reductions.

Abstract: Abstract. In the present work, atmospheric mineral dust from a MACC-II short reanalysis run for 2 years (2007–2008) has been evaluated over northern Africa and the Middle East using satellite aerosol products (from MISR, MODIS and OMI satellite sensors), ground-based AERONET data, in situ PM10 concentrations from AMMA, and extinction vertical profiles from two ground-based lidars and CALIOP satellite-based lidar. The MACC-II aerosol optical depth (AOD) spatial and temporal (seasonal and interannual) variability shows good agreement with those provided by satellite sensors. The capability of the model to reproduce the AOD, Angstrom exponent (AE) and dust optical depth (DOD) from daily to seasonal time-scale is quantified over 26 AERONET stations located in eight geographically distinct regions by using statistical parameters. Overall DOD seasonal variation is fairly well simulated by MACC-II in all regions, although the correlation is significantly higher in dust transport regions than in dust source regions. The ability of MACC-II in reproducing dust vertical profiles has been assessed by comparing seasonal averaged extinction vertical profiles simulated by MACC-II under dust conditions with corresponding extinction profiles obtained with lidar instruments at M'Bour and Santa Cruz de Tenerife, and with CALIOP. We find a good agreement in dust layers structures and averaged extinction vertical profiles between MACC-II, the lidars and CALIOP above the marine boundary layer from 1 to 6 km. Surface dust daily mean concentrations from MACC-II reanalysis has been evaluated with daily averaged PM10 at three monitoring stations of the Sahelian Dust Transect. MACC-II correctly reproduces daily to interannual surface dust concentration variability, although it underestimates daily and monthly means all year long, especially in winter and early spring (dry season). MACC-II reproduces well the dust variability recorded along the station transect which reflects the variability in dust emission by different Saharan sources, but fails in reproducing the sporadic and very strong dust events associated to mesoscale convective systems during the wet season.

TL;DR: In this paper, the influence of variability in wind speed on the calculated gas transfer velocities and the possibility of chemical enhancement of CO2 exchange at low wind speeds over the ocean is illustrated using a quadratic dependence of gas exchange on wind speed.

TL;DR: In this article, a group-contribution method is presented for the prediction of activity coefficients in nonelectrolyte liquid mixtures, which combines the solution-of-functional-groups concept with a model for activity coefficients based on an extension of the quasi chemical theory of liquid mixture (UNIQUAC).

TL;DR: In this paper, an approach to numerical convection is presented that exclusively yields upstream-centered schemes, which start from a meshwise approximation of the initial-value distribution by simple basic functions, e.g., Legendre polynomials.

TL;DR: In this article, the authors proposed a method for estimating the dry deposition velocities of atmospheric gases in the U.S. and surrounding areas and incorporated it into a revised computer code module for use in numerical models of atmospheric transport and deposition of pollutants over regional scales.