> [!CAUTION] > **Caution:** This dataset has been superseded by [NASA/TEMPO/HCHO_L3_V4_QA](https://developers.google.com/earth-engine/datasets/catalog/NASA_TEMPO_HCHO_L3_V4_QA). ![NASA/TEMPO/HCHO_L3_QA](https://developers.google.com/earth-engine/datasets/images/NASA/NASA_TEMPO_HCHO_L3_QA_sample.png) Dataset Availability : 2023-08-01T00:00:00Z--2025-09-16T21:03:09Z Dataset Producer : [QA Filtered: Google and NASA ASDC](https://doi.org/10.5067/IS-40e/TEMPO/HCHO_L3.003) Tags : air-quality formaldehyde nasa pollution satellite-imagery tempo tropomi #### Description Formaldehyde Level 3 collection provides trace gas information on a regular grid covering the TEMPO field of regard for nominal TEMPO observations. Level 3 files are derived by combining information from all Level 2 files constituting a TEMPO East-West scan cycle. The rasters contain information on formaldehyde vertical columns, ancillary data used in air mass factor calculations and reference sector or de-striping corrections, and retrieval quality flags. The re-gridding algorithm uses an area-weighted approach. The QA Filtered TEMPO HCHO L3 dataset is a quality-controlled version of the original data. It is generated by removing data points with high cloud cover (\>50%), extreme solar zenith angle (\>80 degrees), and main data quality (flag \> 0). - A version of this dataset without QA filters applied is available as [NASA/TEMPO/HCHO_L3](https://developers.google.com/earth-engine/datasets/catalog/NASA_TEMPO_HCHO_L3) - [General Documentation](https://asdc.larc.nasa.gov/documents/tempo/guide/TEMPO_Level-2-3_trace_gas_clouds_user_guide_V1.2.pdf) ### Bands **Bands** Pixel size: 2226 meters (all bands) | Name | Units | Pixel Size | Description | |---|---|---|---| | `weight` | km\^2 | 2226 meters | Sum of Level 2 pixel overlap areas. Represents the weighting factor for each grid cell, indicating the fraction of the grid cell area with valid data. | | `vertical_column` | molecules/cm\^2 | 2226 meters | HCHO vertical column | | `vertical_column_uncertainty` | molecules/cm\^2 | 2226 meters | HCHO vertical column uncertainty | | `main_data_quality_flag` | Dimensionless | 2226 meters | Main data quality flag which is always 0, indicating good quality data. | | `num_vertical_column_samples` | Dimensionless | 2226 meters | Number of vertical column samples | | `min_vertical_column_sample` | molecules/cm\^2 | 2226 meters | Smallest vertical column sample | | `max_vertical_column_sample` | molecules/cm\^2 | 2226 meters | Largest vertical column sample | | `solar_zenith_angle` | deg | 2226 meters | Data is filtered to include only observations with solar zenith angle less than or equal to 80 degrees. | | `viewing_zenith_angle` | deg | 2226 meters | Viewing zenith angle at pixel center | | `relative_azimuth_angle` | deg | 2226 meters | Relative azimuth angle at pixel center | | `surface_pressure` | hPa | 2226 meters | Surface pressure | | `terrain_height` | m | 2226 meters | Terrain height | | `snow_ice_fraction` | Dimensionless | 2226 meters | Fraction of pixel area covered by snow and/or ice | | `fitted_slant_column` | molecules/cm\^2 | 2226 meters | HCHO fitted slant column | | `fitted_slant_column_uncertainty` | molecules/cm\^2 | 2226 meters | HCHO fitted slant column uncertainty | | `albedo` | Dimensionless | 2226 meters | Surface albedo | | `amf` | Dimensionless | 2226 meters | HCHO air mass factor | | `eff_cloud_fraction` | Dimensionless | 2226 meters | Data is filtered to include only observations with effective cloud fraction less than or equal to 50%. | | `amf_cloud_fraction` | Dimensionless | 2226 meters | Cloud radiance fraction for AMF calculation | | `amf_cloud_pressure` | hPa | 2226 meters | Cloud pressure for AMF calculation | ### Terms of Use **Terms of Use** This dataset is in the public domain and is available without restriction on use and distribution. See [NASA's Earth Science Data \& Information Policy](https://www.earthdata.nasa.gov/engage/open-data-services-and-software/data-and-information-policy) for additional information. ### Citations Citations: - NASA/LARC/SD/ASDC. (n.d.). TEMPO gridded HCHO vertical columns V03 (PROVISIONAL) \[Data set\]. NASA Langley Atmospheric Science Data Center DAAC. Retrieved from https://doi.org/10.5067/IS-40e/TEMPO/HCHO_L3.003 ### DOIs - ### 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('NASA/TEMPO/HCHO_L3_QA') .filterDate('2024-04-01', '2024-04-05') var visParams = { min: 0, max: 1.5e16, bands: ['vertical_column'], palette: [ '000080', '0000D9', '4000FF', '8000FF', '0080FF', '00D9FF', '80FFFF', 'FF8080', 'D90000', '800000' ] }; Map.setCenter(-95.06, 42.02, 3) Map.addLayer(collection, visParams, 'HCHO vertical column') ``` [Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/NASA/NASA_TEMPO_HCHO_L3_QA) [TEMPO gridded HCHO (QA filtered) vertical columns V03 \[deprecated\]](https://developers.google.com/earth-engine/datasets/catalog/NASA_TEMPO_HCHO_L3_QA) Formaldehyde Level 3 collection provides trace gas information on a regular grid covering the TEMPO field of regard for nominal TEMPO observations. Level 3 files are derived by combining information from all Level 2 files constituting a TEMPO East-West scan cycle. The rasters contain information on formaldehyde vertical columns, ancillary ... NASA/TEMPO/HCHO_L3_QA, air-quality,formaldehyde,nasa,pollution,satellite-imagery,tempo,tropomi 2023-08-01T00:00:00Z/2025-09-16T21:03:09Z -90 -180 90 180 Google Earth Engine https://developers.google.com/earth-engine/datasets - [https://doi.org/10.5067/IS-40e/TEMPO/HCHO_L3.003](https://doi.org/https://doi.org/10.5067/IS-40e/TEMPO/HCHO_L3.003) - [https://doi.org/10.5067/IS-40e/TEMPO/HCHO_L3.003](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/NASA_TEMPO_HCHO_L3_QA)