DOI: 10.23728/fmi-b2share.ccfacc71449046778114b4610e048222
title: Global Air Quality SILAM hindcast v.1.0, 1980-2015
title: The Influence of Air Pollution, Pollen and Ambient Temperature on Asthma and Allergies in Changing Climate (APTA)

description: Data files: APTA_hindcast_metadata.docx Basic information on the APTA hindcast apta_glob__srf.nc4 hourly fields of concentrations for the corresponding year for NH3, NO, NO2, O3, PM10, PM2.5, SO2 MCC_hourly_APTA_AQ_py_.tar.gz time series for cities of the Multi-Country-Multi-City study for CO, NH3, NO2, NO, O3, PM10, PM 2.5, SO2 Descriptions: - Abstract - Methods - Technical info - Contributors
description: Background. Air pollution is a leading cause of mortality and morbidity worldwide. Detailed global assessment of the health effects of short- and long-term exposure to air pollutants requires comprehensive spatio-temporal information on air pollution concentrations over several decades. Currently, empirical measurement data are available for limited time periods only and for a small fraction of the world population. Objectives. To generate, evaluate and analyze a homogeneous multidecadal model hindcast of air quality providing global hourly concentrations for a range of atmospheric pollutants. Methods. We applied the System for Integrated modeLling of Atmospheric coMposition (SILAM) to assess the AQ over the globe in 1980-2015. Results. We produced and evaluated homogeneous hourly time series for O3, NO2, PM2.5, PM10, SO2, CO, NO, NH3 (totally, 86 gaseous and aerosol species) for the period 1980-2015. Discussion. Despite the coarse resolution of the hindcast, inevitable for long-term global simulations, the model skills for several important pollutants, such as PM2.5 and O3, were good, reflecting the comparatively large spatial and long temporal scales of their production from primary pollutants and well-balanced model setup. The trend analysis highlighted the turning points in the pollutant concentration time series. The PM composition reflected the AQ trends in different parts of the world. The computed composition and trends qualitatively agreed with (few) available PM-resolving observations.
description: The hindcast was computed for the period 1980–2015 using the SILAM model version 5.5. The computations were global with a spatial resolution of 1.44° × 1.44° (approx. 150km at equator). The 20 hybrid vertical layers reach up to 10.5 Pa (~64 km); the lowest layer top is at ~90 m. The temporal resolution of the SILAM output is 1 hour. The output variables include 3D concentrations, optical column thickness, and dry and wet deposition of 86 gaseous and aerosol species. From the datasets available at the moment of the simulations, the meteorological data of European ERA-Interim archive were utilized at full resolution, 0.72° × 0.72° and using the vertical coverage with 61 hybrid levels. The anthropogenic emission data were compiled from MACCity for gases and EDGAR (primary aerosols) emission inventories. The vegetation fire emission was applied from the ACCMIP inventory. The biogenic volatile organic compounds emission was used from the MEGAN model hindcast. The NO2 emission from aircrafts and lightning were implemented from the Global Emission InitiAtive GEIA. The emissions of sea salt, wind-blown dust and DMS were computed by SILAM online. The full archive is ~10 TB of size and is available on request. With this dataset, we provide hourly surface concentrations for the key pollutants.
description: The dataset consists of two subsets: 1) The files apta_glob__srf.nc4 are hourly maps of surface concentrations of the main atmospheric pollutants for the specific year. These are the Netcdf 4 files. The units of the fields are provided as attributes to the corresponding fields. 2) The files MCC_hourly_APTA_AQ_py_.tar.gz are zipped tar archives of hourly time series for the corresponding pollutant extracted from the field files for cities participating in the Multi-Country Multi-City public health study MCC. The archive consists of text files, one file per city.