![COPERNICUS/S5P/OFFL/L3_O3_TCL](https://developers.google.com/earth-engine/datasets/images/COPERNICUS/COPERNICUS_S5P_OFFL_L3_O3_TCL_sample.png) Dataset Availability : 2018-04-30T10:50:26Z--2026-10-27T11:33:26Z Dataset Producer : [European Union/ESA/Copernicus](https://sentiwiki.copernicus.eu/web/s5p-products) Revisit Interval : 2 Days Tags : [air-quality](https://developers.google.com/earth-engine/datasets/tags/air-quality.md.txt) [atmosphere](https://developers.google.com/earth-engine/datasets/tags/atmosphere.md.txt) [copernicus](https://developers.google.com/earth-engine/datasets/tags/copernicus.md.txt) [esa](https://developers.google.com/earth-engine/datasets/tags/esa.md.txt) [eu](https://developers.google.com/earth-engine/datasets/tags/eu.md.txt) [o3](https://developers.google.com/earth-engine/datasets/tags/o3.md.txt) [ozone](https://developers.google.com/earth-engine/datasets/tags/ozone.md.txt) [pollution](https://developers.google.com/earth-engine/datasets/tags/pollution.md.txt) [s5p](https://developers.google.com/earth-engine/datasets/tags/s5p.md.txt) [sentinel](https://developers.google.com/earth-engine/datasets/tags/sentinel.md.txt) [tropomi](https://developers.google.com/earth-engine/datasets/tags/tropomi.md.txt) #### Description ### OFFL/L3_O3_TCL This dataset provides offline tropospheric high-resolution imagery of ozone concentrations between 20N and 20S. See also `COPERNICUS/S5P/OFFL/L3_O3` and `COPERNICUS/S5P/NRTI/L3_O3` for the total column data. In the stratosphere, the ozone layer shields the biosphere from dangerous solar ultraviolet radiation. In the troposphere, it acts as an efficient cleansing agent, but at high concentration it also becomes harmful to the health of humans, animals, and vegetation. Ozone is also an important greenhouse-gas contributor to ongoing climate change. Since the discovery of the Antarctic ozone hole in the 1980s and the subsequent Montreal Protocol regulating the production of chlorine-containing ozone-depleting substances, ozone has been routinely monitored from the ground and from space. For this product, the convective cloud differential (ccd) and cloud slicing (csa) algorithm were used. [Product user manual.](https://sentinels.copernicus.eu/documents/247904/2474726/Sentinel-5P-Level-2-Product-User-Manual-Ozone-Tropospheric-Column). [More information.](http://www.tropomi.eu/data-products/tropospheric-ozone-column). Unlike all other S5P products, this product was ingested directly without using `harpconvert`, as it is already a gridded product. Pixels with qa_value\<=70 are masked out. ### Sentinel-5 Precursor Sentinel-5 Precursor is a satellite launched on 13 October 2017 by the European Space Agency to monitor air pollution. The onboard sensor is frequently referred to as Tropomi (TROPOspheric Monitoring Instrument). All of the S5P datasets, except CH~4~, have two versions: Near Real-Time (NRTI) and Offline (OFFL). CH~4~ is available as OFFL only. The NRTI assets cover a smaller area than the OFFL assets, but appear more quickly after acquisition. The OFFL assets contain data from a single orbit (which, due to half the earth being dark, contains data only for a single hemisphere). Because of noise in the data, negative vertical column values are often observed in particular over clean regions or for low SO2 emissions. It is recommended not to filter these values except for outliers, i.e. for vertical columns lower than -0.001 mol/m\^2. The original Sentinel 5P Level 2 (L2) data is binned by time, not by latitude/longitude. To make it possible to ingest the data into Earth Engine, each Sentinel 5P L2 product is converted to L3, keeping a single grid per orbit (that is, no aggregation across products is performed). Source products spanning the antimeridian are ingested as two Earth Engine assets, with suffixes _1 and _2. The conversion to L3 is done by the [harpconvert](https://cdn.rawgit.com/stcorp/harp/master/doc/html/harpconvert.html) tool using the `bin_spatial` operation. The source data is filtered to remove pixels with QA values less than: - 80% for AER_AI - 75% for the tropospheric_NO2_column_number_density band of NO2 - 50% for all other datasets except for O3 and SO2 The O3_TCL product is ingested directly (without running harpconvert). ### Bands **Bands** Pixel size: 111320x55660 meters (all bands) | Name | Units | Pixel Size | Description | |---|---|---|---| | `ozone_tropospheric_mixing_ratio` | mol/m\^2 | 111320x55660 meters | Average tropospheric ozone mixing ratio based on CCD algorithm. | | `ozone_tropospheric_mixing_ratio_precision` | mol/m\^2 | 111320x55660 meters | Standard deviation of tropospheric ozone mixing ratio based on CCD algorithm. | | `ozone_tropospheric_vertical_column` | mol/m\^2 | 111320x55660 meters | Average tropospheric ozone column based on CCD algorithm. | | `ozone_tropospheric_vertical_column_precision` | mol/m\^2 | 111320x55660 meters | Standard deviation of tropospheric ozone column based on CCD algorithm. | | `qa_value` | mol/m\^2 | 111320x55660 meters | A continuous quality descriptor, varying between 0 (no data) and 100 (full quality data). Pixels with qa_value \<= 70 are masked out. | ### Image Properties **Image Properties** | Name | Type | Description | |---|---|---| | ALGORITHM_VERSION | STRING | The algorithm version used in L2 processing. It is separate from the processor (framework) version, to accommodate different release schedules for different products. | | BUILD_DATE | STRING | The date, expressed as milliseconds since 1 Jan 1970, when the software used to perform L2 processing was built. | | HARP_VERSION | INT | The version of the HARP tool used to grid the L2 data into an L3 product. | | INSTITUTION | STRING | The institution where data processing from L1 to L2 was performed. | | L3_PROCESSING_TIME | INT | The date, expressed as milliseconds since 1 Jan 1970, when Google processed the L2 data into L3 using harpconvert. | | LAT_MAX | DOUBLE | The maximum latitude of the asset (degrees). | | LAT_MIN | DOUBLE | The minimum latitude of the asset (degrees). | | LON_MAX | DOUBLE | The maximum longitude of the asset (degrees). | | LON_MIN | DOUBLE | The minimum longitude of the asset (degrees). | | ORBIT | INT | The orbit number of the satellite when the data was acquired. | | PLATFORM | STRING | Name of the platform which acquired the data. | | PROCESSING_STATUS | STRING | The processing status of the product on a global level, mainly based on the availability of auxiliary input data. Possible values are "Nominal" and "Degraded". | | PROCESSOR_VERSION | STRING | The version of the software used for L2 processing, as a string of the form "major.minor.patch". | | PRODUCT_ID | STRING | Id of the L2 product used to generate this asset. | | PRODUCT_QUALITY | STRING | Indicator that specifies whether the product quality is degraded or not. Allowed values are "Degraded" and "Nominal". | | SENSOR | STRING | Name of the sensor which acquired the data. | | SPATIAL_RESOLUTION | STRING | Spatial resolution at nadir. For most products this is `3.5x7 km2`, except for `L2__O3__PR`, which uses `28x21km2`, and `L2__CO____` and `L2__CH4___`, which both use `7x7 km2`. This attribute originates from the CCI standard. | | TIME_REFERENCE_DAYS_SINCE_1950 | INT | Days from 1 Jan 1950 to when the data was acquired. | | TIME_REFERENCE_JULIAN_DAY | DOUBLE | The Julian day number when the data was acquired. | | TRACKING_ID | STRING | UUID for the L2 product file. | ### Terms of Use **Terms of Use** The use of Sentinel data is governed by the [Copernicus Sentinel Data Terms and Conditions.](https://sentinels.copernicus.eu/documents/247904/690755/Sentinel_Data_Legal_Notice) ### Explore with Earth Engine > [!NOTE] > **Important:** Earth Engine is a platform for petabyte-scale scientific analysis and visualization of geospatial datasets, both for public benefit and for business and government users. Earth Engine is free to use for research, education, and nonprofit use. To get started, please [register for Earth Engine access.](https://console.cloud.google.com/earth-engine) ### Code Editor (JavaScript) ```javascript var collection = ee.ImageCollection('COPERNICUS/S5P/OFFL/L3_O3_TCL') .select('ozone_tropospheric_vertical_column') .filterDate('2019-06-01', '2019-07-01'); var band_viz = { min: 0, max: 0.02, palette: ['black', 'blue', 'purple', 'cyan', 'green', 'yellow', 'red'] }; Map.addLayer(collection.mean(), band_viz, 'S5P O3'); Map.setCenter(0.0, 0.0, 2); ``` [Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/COPERNICUS/COPERNICUS_S5P_OFFL_L3_O3_TCL) [Sentinel-5P OFFL O3 TCL: Offline Tropospheric Ozone](https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S5P_OFFL_L3_O3_TCL.md.txt) OFFL/L3_O3_TCL This dataset provides offline tropospheric high-resolution imagery of ozone concentrations between 20N and 20S. See also COPERNICUS/S5P/OFFL/L3_O3 and COPERNICUS/S5P/NRTI/L3_O3 for the total column data. In the stratosphere, the ozone layer shields the biosphere from dangerous solar ultraviolet radiation. In the troposphere, it acts as an efficient cleansing agent, but ... COPERNICUS/S5P/OFFL/L3_O3_TCL, air-quality,atmosphere,copernicus,esa,eu,o3,ozone,pollution,s5p,sentinel,tropomi 2018-04-30T10:50:26Z/2026-10-27T11:33:26Z -90 -180 90 180 Google Earth Engine https://developers.google.com/earth-engine/datasets - [](https://doi.org/https://sentiwiki.copernicus.eu/web/s5p-products) - [](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S5P_OFFL_L3_O3_TCL)