ML-HAPPE

ML-HAPPE#

ML-HAPPE (Machine Learning for Hourly Air Pollution Prediction in England)#

A Framework for Scalable Ambient Air Pollution Concentration Estimation Datasets#

Reliable data on ambient air pollutant concentrations is critical for addressing public health and environmental challenges. However, air pollution monitoring networks in the United Kingdom are sparse, heterogeneous, and often suffer from temporal gaps due to operational issues such as power outages. The dataset presented here addresses these limitations by introducing a scalable, supervised machine learning framework for filling both temporal and spatial data gaps, providing comprehensive hourly pollutant concentration estimates, described in the research paper A framework for scalable ambient air pollution concentration estimation

The underlying machine learning approach employs LightGBM, a gradient-boosting decision-tree-based algorithm known for efficiency and scalability in large-scale modeling. Leveraging real-world observations from sparsely distributed high-quality monitoring stations, the model creates synthetic monitoring station data, generating continuous hourly estimates at a 1 km^2^ spatial resolution across England throughout the entirety of 2018. A total of 355,827 synthetic monitoring stations were produced, significantly expanding the spatial and temporal coverage of air quality data compared to existing monitoring networks.

Dataset Purpose#

This dataset empowers diverse stakeholders, including researchers, policymakers, urban planners, and public health authorities, providing a robust basis for conducting air quality assessments and interventions at unprecedented resolution. The improved granularity facilitates more precise studies into air pollution impacts on human health, urban resilience, and environmental justice, surpassing the capabilities of conventional lower-resolution approaches. The framework’s computational efficiency and scalability further demonstrate its potential applicability for similar pollution estimation challenges globally, especially in regions with limited observational infrastructure.

The dataset is readily accessible and stored online, ensuring rapid retrieval and ease of use for various analytical and operational purposes. Users can confidently perform high-resolution analyses supported by validated machine-learning-driven estimates, thereby enhancing informed decision-making and targeted interventions aimed at reducing air pollution exposure and promoting sustainable urban environments.

For questions regarding this dataset please reach out to Liam J Berrisford.

Air Pollution (Target Vector) Dataset Overview#

The dataset includes hourly estimates for key ambient air pollutants: Nitrogen Dioxide (NO~2~), Nitrogen Oxides (NO~x~), Nitric Oxide (NO), Ozone (O~3~), Particulate Matter with a diameter of 10 μm or less (PM~10~), Particulate Matter with a diameter of 2.5 μm or less (PM~2.5~), and Sulphur Dioxide (SO~2~). Rigorous validation was performed to assess the accuracy of model predictions for forecasting air pollution concentrations, estimating values at previously unmeasured locations, and capturing extreme pollution episodes.

Estimates were produced at the mean, as well as at the 0.05, 0.5, and 0.95 quantiles, to capture both the typical and extreme variations in air pollution concentrations. The mean provides a central tendency estimate, useful for general assessments and long-term policy planning. Quantile-based predictions, specifically at the 0.05, 0.5, and 0.95 quantiles, offer deeper insights into the variability and uncertainty inherent in pollution concentration estimates. These quantile predictions enable stakeholders to understand the range and extremes of pollutant levels, supporting risk assessments and targeted interventions, such as public health advisories or emergency response planning during pollution peaks.

Feature Vector Dataset Overview#

The dataset developed in this study includes a comprehensive set of feature vectors used to estimate ambient air pollution concentrations across England. Feature vectors represent environmental conditions and phenomena known to influence air pollutant concentrations, including meteorological variables (e.g., wind speed and temperature), emissions from various human activities (e.g., traffic intensity, industrial processes), land-use classifications, and remotely sensed air pollution measurements. Each feature was selected based on established scientific evidence linking these variables to the formation, dispersion, and accumulation of air pollutants. Incorporating such a diverse and detailed set of features enables the machine learning model to robustly capture complex spatial and temporal variations in air quality, ultimately improving the accuracy and applicability of pollution estimates.

Data Description#

Data description
Data type	Point Estimates
Projection	EPSG:3395 WGS 84 / World Mercator
Horizontal coverage	England
Horizontal resolution	1km^2^
Vertical coverage	Surface only
Vertical resolution	Single layer
Temporal coverage	2018
Temporal resolution	Hourly
File format	NetCDF
Update frequency	Static

Coordinate Variables#

Name	Units	Description
Timestamp	N/A	Time coordinate (hourly resolution)
Easting	m	Easting of centroid (EPSG:3395)
Northing	m	Northing of centroid (EPSG:3395)

Each NetCDF file is indexed by (Timestamp, Northing, Easting).

Data Variables#

Output Variables#

Name	Units	Description
UK Model Grid ID	–	Unique identifier for each grid in the UK model, synthetic monitoring station locations are based on grid centroids.
no Prediction 0.05 Quantile	µg/m^3^	Estimated 5th percentile of modelled NO concentration.
no Prediction 0.5 Quantile	µg/m^3^	Estimated 50th percentile (median) of modelled NO concentration.
no Prediction 0.95 Quantile	µg/m^3^	Estimated 95th percentile of modelled NO concentration.
no Prediction Mean	µg/m^3^	Estimated mean of modelled NO concentration.
no2 Prediction 0.05 Quantile	µg/m^3^	Estimated 5th percentile of modelled NO~2~ concentration.
no2 Prediction 0.5 Quantile	µg/m^3^	Estimated 50th percentile (median) of modelled NO~2~ concentration.
no2 Prediction 0.95 Quantile	µg/m^3^	Estimated 95th percentile of modelled NO~2~ concentration.
no2 Prediction Mean	µg/m^3^	Estimated mean of modelled NO~2~ concentration.
nox Prediction 0.05 Quantile	µg/m^3^	Estimated 5th percentile of modelled NO~x~ concentration.
nox Prediction 0.5 Quantile	µg/m^3^	Estimated 50th percentile (median) of modelled NO~x~ concentration.
nox Prediction 0.95 Quantile	µg/m^3^	Estimated 95th percentile of modelled NO~x~ concentration.
nox Prediction Mean	µg/m^3^	Estimated mean of modelled NO~x~ concentration.
o3 Prediction 0.05 Quantile	µg/m^3^	Estimated 5th percentile of modelled O~3~ concentration.
o3 Prediction 0.5 Quantile	µg/m^3^	Estimated 50th percentile (median) of modelled O~3~ concentration.
o3 Prediction 0.95 Quantile	µg/m^3^	Estimated 95th percentile of modelled O~3~ concentration.
o3 Prediction Mean	µg/m^3^	Estimated mean of modelled O~3~ concentration.
pm10 Prediction 0.05 Quantile	µg/m^3^	Estimated 5th percentile of modelled PM~10~ concentration.
pm10 Prediction 0.5 Quantile	µg/m^3^	Estimated 50th percentile (median) of modelled PM~10~ concentration.
pm10 Prediction 0.95 Quantile	µg/m^3^	Estimated 95th percentile of modelled PM~10~ concentration.
pm10 Prediction Mean	µg/m^3^	Estimated mean of modelled PM~10~ concentration.
pm2.5 Prediction 0.05 Quantile	µg/m^3^	Estimated 5th percentile of modelled PM~2.5~ concentration.
pm2.5 Prediction 0.5 Quantile	µg/m^3^	Estimated 50th percentile (median) of modelled PM~2.5~ concentration.
pm2.5 Prediction 0.95 Quantile	µg/m^3^	Estimated 95th percentile of modelled PM~2.5~ concentration.
pm2.5 Prediction Mean	µg/m^3^	Estimated mean of modelled PM~2.5~ concentration.
so2 Prediction 0.05 Quantile	µg/m^3^	Estimated 5th percentile of modelled SO~2~ concentration.
so2 Prediction 0.5 Quantile	µg/m^3^	Estimated 50th percentile (median) of modelled SO~2~ concentration.
so2 Prediction 0.95 Quantile	µg/m^3^	Estimated 95th percentile of modelled SO~2~ concentration.
so2 Prediction Mean	µg/m^3^	Estimated mean of modelled SO~2~ concentration.

Input Variables#

Name	Units	Description
100m U Component of Wind	m/s	East–west wind component at 100 m above ground level.
100m V Component of Wind	m/s	North–south wind component at 100 m above ground level.
10m U Component of Wind	m/s	East–west wind component at 10 m above ground level.
10m V Component of Wind	m/s	North–south wind component at 10 m above ground level.
2m Dewpoint Temperature	K	Temperature at which air becomes saturated, measured at 2 m above ground level.
2m Temperature	K	Air temperature at 2 m above ground level.
Boundary Layer Height	m	Height of the atmospheric boundary layer above ground level.
Downward UV Radiation at the Surface	W/m^2^	Downward ultraviolet radiant flux received at Earth’s surface.
Instantaneous 10m Wind Gust	m/s	Peak wind gust speed observed at 10 m AGL over a short time interval.
Surface Pressure	hPa	Atmospheric pressure at ground level.
Total Column Rain Water	kg/m^2^	Vertically integrated amount of rain water in a column of air above the surface.
Sentinel 5P AAI	-	Absorbing Aerosol Index (AAI), indicating the presence of UV-absorbing aerosols in the atmosphere.
Sentinel 5P CO	mol/m^2^	Total column amount of carbon monoxide (CO) retrieved from Sentinel‑5P.
Sentinel 5P HCHO	mol/m^2^	Total column amount of formaldehyde (HCHO) retrieved from Sentinel‑5P.
Sentinel 5P NO2	mol/m^2^	Tropospheric column amount of nitrogen dioxide (NO₂) from Sentinel‑5P.
Sentinel 5P O3	mol/m^2^	Total column ozone (O₃) retrieved by Sentinel‑5P.
Day of Week Number	-	Integer representing the weekday, for example 0 (Monday )– 6 (Sunday).
Hour Number	-	Hour of the day on a 24-hour clock, for example 0 (midnight) – 23 (11 pm).
Month Number	-	Integer representing the month, for example 1 (January) – 12 (December).
Week Number	-	Integer denoting the ISO week number (1-53)
Bicycle Score	-	Hourly traffic-flow score for bicycles in each 1 km^2^ grid, aggregated from DfT AADF data and temporally distributed via the UK Time Use Survey.
Bus and Coach Score	-	Hourly traffic-flow score for buses and coaches in each 1 km^2^ grid, aggregated from DfT AADF data and temporally distributed via the UK Time Use Survey.
Car and Taxi Score	-	Hourly traffic-flow score for cars and taxis in each 1 km^2^ grid, aggregated from DfT AADF data and temporally distributed via the UK Time Use Survey.
HGV Score	-	Hourly traffic-flow score for heavy goods vehicles (HGVs) in each 1 km^2^ grid, aggregated from DfT AADF data and temporally distributed via the UK Time Use Survey.
LGV Score	-	Hourly traffic-flow score for light goods vehicles (LGVs) in each 1 km^2^ grid, aggregated from DfT AADF data and temporally distributed via the UK Time Use Survey.
Acid grassland	-	Fraction of the 1 km^2^ grid area classified as Acid grassland, derived from UKCEH 25 m Land Cover Maps.
Arable and Horticulture	-	Fraction of the 1 km^2^ grid area classified as Arable and Horticulture, derived from UKCEH 25 m Land Cover Maps.
Bog	-	Fraction of the 1 km^2^ grid area classified as Bog, derived from UKCEH 25 m Land Cover Maps.
Broadleaved woodland	-	Fraction of the 1 km^2^ grid area classified as Broadleaved woodland, derived from UKCEH 25 m Land Cover Maps.
Calcareous Grassland	-	Fraction of the 1 km^2^ grid area classified as Calcareous Grassland, derived from UKCEH 25 m Land Cover Maps.
Coniferous Woodland	-	Fraction of the 1 km^2^ grid area classified as Coniferous Woodland, derived from UKCEH 25 m Land Cover Maps.
Fen Marsh and Swamp	-	Fraction of the 1 km^2^ grid area classified as Fen, Marsh, or Swamp, derived from UKCEH 25 m Land Cover Maps.
Freshwater	-	Fraction of the 1 km^2^ grid area covered by Freshwater, derived from UKCEH 25 m Land Cover Maps.
Heather	-	Fraction of the 1 km^2^ grid area classified as Heather, derived from UKCEH 25 m Land Cover Maps.
Heather grassland	-	Fraction of the 1 km^2^ grid area classified as Heather grassland, derived from UKCEH 25 m Land Cover Maps.
Improved Grassland	-	Fraction of the 1 km^2^ grid area classified as Improved Grassland, derived from UKCEH 25 m Land Cover Maps.
Inland Rock	-	Fraction of the 1 km^2^ grid area classified as Inland Rock, derived from UKCEH 25 m Land Cover Maps.
Littoral Rock	-	Fraction of the 1 km^2^ grid area classified as Littoral Rock, derived from UKCEH 25 m Land Cover Maps.
Littoral sediment	-	Fraction of the 1 km^2^ grid area classified as Littoral sediment, derived from UKCEH 25 m Land Cover Maps.
Neutral Grassland	-	Fraction of the 1 km^2^ grid area classified as Neutral Grassland, derived from UKCEH 25 m Land Cover Maps.
No Land	-	Fraction of the 1 km^2^ grid area flagged as No Land, derived from UKCEH 25 m Land Cover Maps.
Saltmarsh	-	Fraction of the 1 km^2^ grid area classified as Saltmarsh, derived from UKCEH 25 m Land Cover Maps.
Saltwater	-	Fraction of the 1 km^2^ grid area classified as Saltwater, derived from UKCEH 25 m Land Cover Maps.
Suburban	-	Fraction of the 1 km^2^ grid area flagged as Suburban, derived from UKCEH 25 m Land Cover Maps.
Supra-littoral Rock	-	Fraction of the 1 km^2^ grid area classified as Supra-littoral Rock, derived from UKCEH 25 m Land Cover Maps.
Supra-littoral Sediment	-	Fraction of the 1 km^2^ grid area classified as Supra-littoral Sediment, derived from UKCEH 25 m Land Cover Maps.
Urban	-	Fraction of the 1 km^2^ grid area flagged as Urban, derived from UKCEH 25 m Land Cover Maps.
NAEI SNAP 1 CO	kilotonne	Hourly emission flux of CO from SNAP sector 1 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 1 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 1 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 1 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 1 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 1 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 1 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 1 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 1 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 1 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 1 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 1 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 1 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 10 CO	kilotonne	Hourly emission flux of CO from SNAP sector 10 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 10 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 10 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 10 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 10 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 10 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 10 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 10 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 10 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 10 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 10 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 10 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 10 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 11 CO	kilotonne	Hourly emission flux of CO from SNAP sector 11 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 11 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 11 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 11 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 11 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 11 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 11 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 11 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 11 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 11 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 11 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 11 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 11 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 2 CO	kilotonne	Hourly emission flux of CO from SNAP sector 2 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 2 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 2 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 2 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 2 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 2 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 2 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 2 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 2 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 2 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 2 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 2 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 2 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 3 CO	kilotonne	Hourly emission flux of CO from SNAP sector 3 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 3 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 3 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 3 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 3 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 3 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 3 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 3 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 3 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 3 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 3 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 3 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 3 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 4 CO	kilotonne	Hourly emission flux of CO from SNAP sector 4 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 4 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 4 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 4 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 4 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 4 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 4 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 4 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 4 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 4 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 4 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 4 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 4 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 5 CO	kilotonne	Hourly emission flux of CO from SNAP sector 5 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 5 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 5 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 5 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 5 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 5 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 5 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 5 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 5 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 5 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 5 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 5 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 5 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 6 CO	kilotonne	Hourly emission flux of CO from SNAP sector 6 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 6 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 6 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 6 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 6 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 6 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 6 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 6 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 6 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 6 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 6 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 6 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 6 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 7 CO	kilotonne	Hourly emission flux of CO from SNAP sector 7 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 7 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 7 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 7 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 7 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 7 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 7 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 7 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 7 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 7 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 7 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 7 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 7 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 8 CO	kilotonne	Hourly emission flux of CO from SNAP sector 8 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 8 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 8 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 8 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 8 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 8 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 8 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 8 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 8 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 8 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 8 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 8 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 8 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 9 CO	kilotonne	Hourly emission flux of CO from SNAP sector 9 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 9 NH3	kilotonne	Hourly emission flux of NH~3~ from SNAP sector 9 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 9 NMVOC	kilotonne	Hourly emission flux of NMVOC from SNAP sector 9 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 9 NOx	kilotonne	Hourly emission flux of NO~x~ from SNAP sector 9 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 9 PM10	kilotonne	Hourly emission flux of PM~10~ from SNAP sector 9 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 9 PM25	kilotonne	Hourly emission flux of PM~2.5~ from SNAP sector 9 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
NAEI SNAP 9 SOx	kilotonne	Hourly emission flux of SO~x~ from SNAP sector 9 in each 1 km^2^ grid cell, aggregated from NAEI data and scaled by temporal factors.
Road Infrastructure Distance Residential	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Residential road, derived from OpenStreetMaps.
Road Infrastructure Distance Footway	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Footway, derived from OpenStreetMaps.
Road Infrastructure Distance Service	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Service road, derived from OpenStreetMaps.
Road Infrastructure Distance Primary	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Primary road, derived from OpenStreetMaps.
Road Infrastructure Distance Path	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Path, derived from OpenStreetMaps.
Road Infrastructure Distance Cycleway	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Cycleway, derived from OpenStreetMaps.
Road Infrastructure Distance Tertiary	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Tertiary road, derived from OpenStreetMaps.
Road Infrastructure Distance Secondary	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Secondary road, derived from OpenStreetMaps.
Road Infrastructure Distance Unclassified	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Unclassified road, derived from OpenStreetMaps.
Road Infrastructure Distance Track	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Track, derived from OpenStreetMaps.
Road Infrastructure Distance Trunk	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Trunk road, derived from OpenStreetMaps.
Road Infrastructure Distance Motorway	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Motorway, derived from OpenStreetMaps.
Road Infrastructure Distance Pedestrian	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Pedestrian road, derived from OpenStreetMaps.
Road Infrastructure Distance Living Street	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Living Street, derived from OpenStreetMaps.
Total Length Residential	m	Summed length (meters) of all Residential road segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Footway	m	Summed length (meters) of all Footway segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Service	m	Summed length (meters) of all Service road segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Primary	m	Summed length (meters) of all Primary road segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Path	m	Summed length (meters) of all Path segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Cycleway	m	Summed length (meters) of all Cycleway segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Tertiary	m	Summed length (meters) of all Tertiary road segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Secondary	m	Summed length (meters) of all Secondary road segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Unclassified	m	Summed length (meters) of all Unclassified road segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Track	m	Summed length (meters) of all Track segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Trunk	m	Summed length (meters) of all Trunk road segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Motorway	m	Summed length (meters) of all Motorway segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Pedestrian	m	Summed length (meters) of all Pedestrian-classified segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Living Street	m	Summed length (meters) of all Living Street road segments within each 1km^2^ grid, derived from OpenStreetMaps.
Road Infrastructure Distance Bridleway	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Bridleway, derived from OpenStreetMaps.
Road Infrastructure Distance Construction	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Construction road, derived from OpenStreetMaps.
Road Infrastructure Distance Motorway Link	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Motorway Link, derived from OpenStreetMaps.
Road Infrastructure Distance Primary Link	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Primary Link, derived from OpenStreetMaps.
Road Infrastructure Distance Raceway	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Raceway, derived from OpenStreetMaps.
Road Infrastructure Distance Secondary Link	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Secondary Link, derived from OpenStreetMaps.
Road Infrastructure Distance Steps	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Steps, derived from OpenStreetMaps.
Road Infrastructure Distance Tertiary Link	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Tertiary Link, derived from OpenStreetMaps.
Road Infrastructure Distance Trunk Link	m	Distance (meters) from the 1 km^2^ grid centroid to the nearest Trunk Link, derived from OpenStreetMaps.
Total Length Bridleway	m	Summed length (meters) of all Bridleway segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Construction	m	Summed length (meters) of all Construction-classified road segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Motorway Link	m	Summed length (meters) of all Motorway Link segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Primary Link	m	Summed length (meters) of all Primary Link segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Raceway	m	Summed length (meters) of all Raceway segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Secondary Link	m	Summed length (meters) of all Secondary Link segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Steps	m	Summed length (meters) of all Steps within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Tertiary Link	m	Summed length (meters) of all Tertiary Link segments within each 1km^2^ grid, derived from OpenStreetMaps.
Total Length Trunk Link	m	Summed length (meters) of all Trunk Link segments within each 1km^2^ grid, derived from OpenStreetMaps.