Sentinel-5P OFFL O3 TCL: Offline Tropospheric Ozone

COPERNICUS/S5P/OFFL/L3_O3_TCL
Dataset Availability
2018-04-30T10:50:26Z–2024-12-14T11:04:12Z
Dataset Provider
Earth Engine Snippet
ee.ImageCollection("COPERNICUS/S5P/OFFL/L3_O3_TCL")
Revisit Interval
2 Days
Tags
air-quality copernicus esa eu o3 ozone pollution s5p sentinel tropomi

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.. More information..

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 CH4, have two versions: Near Real-Time (NRTI) and Offline (OFFL). CH4 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 on 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 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

Resolution
111320 meters

Y Resolution
55660 meters

Bands

Name Units Description
ozone_tropospheric_mixing_ratio mol/m^2

Average tropospheric ozone mixing ratio based on CCD algorithm.
ozone_tropospheric_mixing_ratio_precision mol/m^2

Standard deviation of tropospheric ozone mixing ratio based on CCD algorithm.
ozone_tropospheric_vertical_column mol/m^2

Average tropospheric ozone column based on CCD algorithm.
ozone_tropospheric_vertical_column_precision mol/m^2

Standard deviation of tropospheric ozone column based on CCD algorithm.
qa_value mol/m^2

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 3.5x7km2, except for L2__O3__PR, which uses 28x21km2, and L2__CO____ and L2__CH4___, which both use 7x7km2. 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.

Explore with Earth Engine

Code Editor (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
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,copernicus,esa,eu,o3,ozone,pollution,s5p,sentinel,tropomi
2018-04-30T10:50:26Z/2024-12-14T11:04:12Z
Google Earth Engine