We detect and quantify NOx point sources from the divergence of the horizontal NOx flux based on the continuity equation. The analysis steps are: - The NOx flux is determined for each TROPOMI (TROPOspheric Monitoring Instrument) orbit by upscaling the TROPOMI tropospheric NO2 column to NOx and multiplying it with horizontal wind fields from ECMWF (300m above ground). - The NOx fluxes are averaged for 2018-2019. - The divergence, i.e. spatial derivative, of the mean NOx flux is calculated, which is particularly sensitive for point sources. - NOx point sources are detected in the divergence map by an automated search algorithm for local maxima, and quantified by fitting a Gaussian function to these maxima. Ambiguous cases are skipped. TROPOMI is the satellite instrument on board of the Copernicus Sentinel-5 Precursor satellite. The approach of deriving emission information from the divergence of the NOx flux is described in Beirle et al., 2019: Beirle, S., Borger, C., Dörner, S., Li, A., Hu, Z., Liu, F., Wang, Y. and Wagner, T.: Pinpointing nitrogen oxide emissions from space, Science Advances, 5(11), eaax9800, doi:10.1126/sciadv.aax9800, 2019. The details and modifications made for the automated detection of NOx point sources on global scale are provided in Beirle et al., 2020: Beirle, S., Borger, C., Dörner, S., Eskes, H., Kumar, V., de Laat, A., and Wagner, T.: Catalog of NOx emissions from point sources as derived from the divergence of the NO2 flux for TROPOMI, to be submitted to Earth System Science Data, 2020.
We detect and quantify NOx point sources from the divergence of the horizontal NOx flux based on the continuity equation. The analysis steps are: - The NOx flux is determined for each TROPOMI (TROPOspheric Monitoring Instrument) orbit by upscaling the TROPOMI tropospheric NO2 column to NOx and multiplying it with horizontal wind fields from ECMWF (300m above ground). - The NOx fluxes are averaged for 2018-2019. - The divergence, i.e. spatial derivative, of the mean NOx flux is calculated, which is particularly sensitive for point sources. - NOx point sources are detected in the divergence map by an automated search algorithm for local maxima, and quantified by fitting a Gaussian function to these maxima. Ambiguous cases are skipped. TROPOMI is the satellite instrument on board of the Copernicus Sentinel-5 Precursor satellite. The approach of deriving emission information from the divergence of the NOx flux is described in Beirle et al., 2019: Beirle, S., Borger, C., Dörner, S., Li, A., Hu, Z., Liu, F., Wang, Y. and Wagner, T.: Pinpointing nitrogen oxide emissions from space, Science Advances, 5(11), eaax9800, doi:10.1126/sciadv.aax9800, 2019. The details and modifications made for the automated detection of NOx point sources on global scale are provided in Beirle et al., 2020: Beirle, S., Borger, C., Dörner, S., Eskes, H., Kumar, V., de Laat, A., and Wagner, T.: Catalog of NOx emissions from point sources as derived from the divergence of the NO2 flux for TROPOMI, to be submitted to Earth System Science Data, 2020.
We present an updated (v2) catalog of NOx emissions from point sources as derived from TROPOMI measurements of NO2 (PAL product, May 2018 - Nov 2021) combined with wind fields from ERA5. Compared to version 1 of the catalog, several improvements have been introduced to the algorithm. Most importantly, several corrections are applied, accounting for the effects of plume height on satellite sensitivity, 3D topographic effects, and the chemical loss of NOx , resulting in considerably higher and more accurate NOx emissions. In addition, error estimates are provided for each point source, taking into account the uncertainties of the individual retrieval steps. The catalog v2 is based on a fully automated iterative detection algorithm of point sources worldwide. It lists 1139 locations that have been found to be significant NOx sources. The majority of these locations match to power plants listed in the global power plant database. Other NOx point sources correspond to cement plants, metal smelters, industrial areas, or medium-sized cities.
The TROPOMI instrument onboard the Copernicus SENTINEL-5 Precursor satellite is a nadir-viewing, imaging spectrometer that provides global measurements of atmospheric properties and constituents on a daily basis. It is contributing to monitoring air quality and climate, providing critical information to services and decision makers. The instrument uses passive remote sensing techniques by measuring the top of atmosphere solar radiation reflected by and radiated from the earth and its atmosphere. The four spectrometers of TROPOMI cover the ultraviolet (UV), visible (VIS), Near Infra-Red (NIR) and Short Wavelength Infra-Red (SWIR) domains of the electromagnetic spectrum. The operational trace gas products generated at DLR on behave ESA are: Ozone (O3), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2), Formaldehyde (HCHO), Carbon Monoxide (CO) and Methane (CH4), together with clouds and aerosol properties. Daily observations are binned onto a regular latitude-longitude grid. This product displays the ozone (O3) concentration globally (in Dobson Unit). The ozone layer in the stratosphere protects the biosphere from harmful solar ultraviolet radiation. Ozone in troposphere can pose risks to the health of humans, animals, and vegetation. This product is generated in the scope of the DLR project INPULS. INPULS develops (a) innovative retrieval algorithms and processors for the generation of value-added products from the atmospheric Copernicus missions Sentinel-5 Precursor, Sentinel-4, and Sentinel-5, (b) cloud-based (re)processing systems, (c) improved data discovery and access technologies as well as server-side analytics for the users, and (d) data visualization services.
The TROPOMI instrument onboard the Copernicus SENTINEL-5 Precursor satellite is a nadir-viewing, imaging spectrometer that provides global measurements of atmospheric properties and constituents on a daily basis. It is contributing to monitoring air quality and climate, providing critical information to services and decision makers. The instrument uses passive remote sensing techniques by measuring the top of atmosphere solar radiation reflected by and radiated from the earth and its atmosphere. The four spectrometers of TROPOMI cover the ultraviolet (UV), visible (VIS), Near Infra-Red (NIR) and Short Wavelength Infra-Red (SWIR) domains of the electromagnetic spectrum. The operational trace gas products generated at DLR on behave ESA are: Ozone (O3), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2), Formaldehyde (HCHO), Carbon Monoxide (CO) and Methane (CH4), together with clouds and aerosol properties. This product displays the sulphur dioxide (SO2) concentration around the globe. Sulphur dioxide enters the atmosphere through volcanic eruptions and human-related activities. Daily observations are binned onto a regular latitude-longitude grid. This product is created in the scope of the project INPULS. The DLR INPULS project develops (a) innovative retrieval algorithms and processors for the generation of value-added products from the atmospheric Copernicus missions Sentinel-5 Precursor, Sentinel-4, and Sentinel-5, (b) cloud-based (re)processing systems, (c) improved data discovery and access technologies as well as server-side analytics for the users, and (d) data visualization services.
The TROPOMI instrument onboard the Copernicus SENTINEL-5 Precursor satellite is a nadir-viewing, imaging spectrometer that provides global measurements of atmospheric properties and constituents on a daily basis. It is contributing to monitoring air quality and climate, providing critical information to services and decision makers. The instrument uses passive remote sensing techniques by measuring the top of atmosphere solar radiation reflected by and radiated from the earth and its atmosphere. The four spectrometers of TROPOMI cover the ultraviolet (UV), visible (VIS), Near Infra-Red (NIR) and Short Wavelength Infra-Red (SWIR) domains of the electromagnetic spectrum. The operational trace gas products generated at DLR on behave ESA are: Ozone (O3), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2), Formaldehyde (HCHO), Carbon Monoxide (CO) and Methane (CH4), together with clouds and aerosol properties. This product displays the Cloud Optical Thickness (COT) around the globe. Clouds play a crucial role in the Earth's climate system and have significant effects on trace gas retrievals. The cloud optical thickness is retrieved from the O2-A band using the ROCINN algorithm. Daily observations are binned onto a regular latitude-longitude grid. This product is created in the scope of the project INPULS. It develops (a) innovative retrieval algorithms and processors for the generation of value-added products from the atmospheric Copernicus missions Sentinel-5 Precursor, Sentinel-4, and Sentinel-5, (b) cloud-based (re)processing systems, (c) improved data discovery and access technologies as well as server-side analytics for the users, and (d) data visualization services.
The TROPOMI instrument onboard the Copernicus SENTINEL-5 Precursor satellite is a nadir-viewing, imaging spectrometer that provides global measurements of atmospheric properties and constituents on a daily basis. It is contributing to monitoring air quality and climate, providing critical information to services and decision makers. The instrument uses passive remote sensing techniques by measuring the top of atmosphere solar radiation reflected by and radiated from the earth and its atmosphere. The four spectrometers of TROPOMI cover the ultraviolet (UV), visible (VIS), Near Infra-Red (NIR) and Short Wavelength Infra-Red (SWIR) domains of the electromagnetic spectrum. The operational trace gas products generated at DLR on behave ESA are: Ozone (O3), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2), Formaldehyde (HCHO), Carbon Monoxide (CO) and Methane (CH4), together with clouds and aerosol properties. This product displays the Cloud-Top Height (CTH) around the globe. Clouds play a crucial role in the Earth's climate system and have significant effects on trace gas retrievals. The cloud-top height is retrieved from the O2-A band using the ROCINN algorithm. Daily observations are binned onto a regular latitude-longitude grid. This product is created in the scope of the project INPULS. It develops (a) innovative retrieval algorithms and processors for the generation of value-added products from the atmospheric Copernicus missions Sentinel-5 Precursor, Sentinel-4, and Sentinel-5, (b) cloud-based (re)processing systems, (c) improved data discovery and access technologies as well as server-side analytics for the users, and (d) data visualization services.
The TROPOMI instrument onboard the Copernicus SENTINEL-5 Precursor satellite is a nadir-viewing, imaging spectrometer that provides global measurements of atmospheric properties and constituents on a daily basis. It is contributing to monitoring air quality and climate, providing critical information to services and decision makers. The instrument uses passive remote sensing techniques by measuring the top of atmosphere solar radiation reflected by and radiated from the earth and its atmosphere. The four spectrometers of TROPOMI cover the ultraviolet (UV), visible (VIS), Near Infra-Red (NIR) and Short Wavelength Infra-Red (SWIR) domains of the electromagnetic spectrum. The operational trace gas products generated at DLR on behave ESA are: Ozone (O3), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2), Formaldehyde (HCHO), Carbon Monoxide (CO) and Methane (CH4), together with clouds and aerosol properties. This product displays the Formaldehyde (HCHO) concentration around the globe. The major HCHO sources are vegetation, fires, traffic and industrial sources. Daily observations are binned onto a regular latitude-longitude grid. This product is created in the scope of the project INPULS. It develops (a) innovative retrieval algorithms and processors for the generation of value-added products from the atmospheric Copernicus missions Sentinel-5 Precursor, Sentinel-4, and Sentinel-5, (b) cloud-based (re)processing systems, (c) improved data discovery and access technologies as well as server-side analytics for the users, and (d) data visualization services.
The TROPOMI instrument onboard the Copernicus SENTINEL-5 Precursor satellite is a nadir-viewing, imaging spectrometer that provides global measurements of atmospheric properties and constituents on a daily basis. It is contributing to monitoring air quality and climate, providing critical information to services and decision makers. The instrument uses passive remote sensing techniques by measuring the top of atmosphere solar radiation reflected by and radiated from the earth and its atmosphere. The four spectrometers of TROPOMI cover the ultraviolet (UV), visible (VIS), Near Infra-Red (NIR) and Short Wavelength Infra-Red (SWIR) domains of the electromagnetic spectrum. The operational trace gas products generated at DLR on behave ESA are: Ozone (O3), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2), Formaldehyde (HCHO), Carbon Monoxide (CO) and Methane (CH4), together with clouds and aerosol properties. This product displays the Nitrogen Dioxide (NO2) near surface concentration for Germany and neighboring countries as derived from the POLYPHEMUS/DLR air quality model. Surface NO2 is mainly generated by anthropogenic sources, e.g. transport and industry. POLYPHEMUS/DLR is a state-of-the-art air quality model taking into consideration - meteorological conditions, - photochemistry, - anthropogenic and natural (biogenic) emissions, - TROPOMI NO2 observations for data assimilation. This Level 4 air quality product (surface NO2 at 15:00 UTC) is based on innovative algorithms, processors, data assimilation schemes and operational processing and dissemination chain developed in the framework of the INPULS project. The DLR project INPULS develops (a) innovative retrieval algorithms and processors for the generation of value-added products from the atmospheric Copernicus missions Sentinel-5 Precursor, Sentinel-4, and Sentinel-5, (b) cloud-based (re)processing systems, (c) improved data discovery and access technologies as well as server-side analytics for the users, and (d) data visualization services.
The TROPOMI instrument onboard the Copernicus SENTINEL-5 Precursor satellite is a nadir-viewing, imaging spectrometer that provides global measurements of atmospheric properties and constituents on a daily basis. It is contributing to monitoring air quality and climate, providing critical information to services and decision makers. The instrument uses passive remote sensing techniques by measuring the top of atmosphere solar radiation reflected by and radiated from the earth and its atmosphere. The four spectrometers of TROPOMI cover the ultraviolet (UV), visible (VIS), Near Infra-Red (NIR) and Short Wavelength Infra-Red (SWIR) domains of the electromagnetic spectrum. The operational trace gas products generated at DLR on behave ESA are: Ozone (O3), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2), Formaldehyde (HCHO), Carbon Monoxide (CO) and Methane (CH4), together with clouds and aerosol properties. This product displays the Cloud Fraction (CF) around the globe. Clouds play a crucial role in the Earth's climate system and have significant effects on trace gas retrievals. The radiometric cloud fraction is retrieved from the UV using the OCRA algorithm. Daily observations are binned onto a regular latitude-longitude grid. This product is created in the scope of the project INPULS. It develops (a) innovative retrieval algorithms and processors for the generation of value-added products from the atmospheric Copernicus missions Sentinel-5 Precursor, Sentinel-4, and Sentinel-5, (b) cloud-based (re)processing systems, (c) improved data discovery and access technologies as well as server-side analytics for the users, and (d) data visualization services.