Zhao, Xuepeng; and NOAA CDR Program: NOAA Climate Data Record (CDR)
of AVHRR Daily and Monthly Aerosol Optical Thickness (AOT) over Global
Oceans, Version 4.0. [indicate subset used]。NOAA National Centers for Environmental Information（NCEI）。doi:10.25921/w3zj-4y48 [アクセス日]。
[null,null,[],[[["\u003cp\u003eThe NOAA CDR of Aerosol Optical Thickness (AOT) provides daily global data at 0.1-degree resolution, derived from AVHRR imagery.\u003c/p\u003e\n"],["\u003cp\u003eThis dataset focuses on aerosol optical thickness over non-glint water surfaces during daytime, with data spanning from 1981 to 2024.\u003c/p\u003e\n"],["\u003cp\u003eAerosol optical thickness values range from -0.19 to 4.95, indicating the degree to which aerosols prevent light transmission in the atmosphere.\u003c/p\u003e\n"],["\u003cp\u003eThe dataset is freely available for research, education, and non-profit use with no restrictions on its use.\u003c/p\u003e\n"],["\u003cp\u003eThis data is provided by NOAA's National Climatic Data Center and can be easily accessed and analyzed using Google Earth Engine.\u003c/p\u003e\n"]]],[],null,["# NOAA CDR AVHRR AOT: Daily Aerosol Optical Thickness Over Global Oceans, v04\n\nDataset Availability\n: 1981-01-01T00:00:00Z--2025-06-25T00:00:00Z\n\nDataset Provider\n:\n\n\n [NOAA](https://doi.org/10.25921/w3zj-4y48)\n\nCadence\n: 1 Day\n\nTags\n:\n [aerosol](/earth-engine/datasets/tags/aerosol) [atmosphere](/earth-engine/datasets/tags/atmosphere) [atmospheric](/earth-engine/datasets/tags/atmospheric) [avhrr](/earth-engine/datasets/tags/avhrr) [cdr](/earth-engine/datasets/tags/cdr) [daily](/earth-engine/datasets/tags/daily) [noaa](/earth-engine/datasets/tags/noaa) [optical](/earth-engine/datasets/tags/optical) [pollution](/earth-engine/datasets/tags/pollution) \naot \n\n#### Description\n\nThe NOAA Climate Data Record (CDR) of Aerosol Optical Thickness (AOT) is a\ncollection of global daily 0.1 degree derived data from the PATMOS-x AVHRR\nlevel-2b channel 1 (0.63 micron) orbital clear-sky radiance. The aerosol\nproduct is generated from AVHRR imagery in cloud-free conditions during\ndaytime over oceans.\n\nDue to the relatively large uncertainties associated with surface\nreflectance over water glint area and land surface as well as limited\nAVHRR retrieval channels, this dataset only includes retrieval over\nnon-glint water surface (specifically at the anti-solar side of the orbit\nwith viewing angle more than 40 degree away from the specular ray). For\nmore details, see the [Algorithm Description](https://www.ncei.noaa.gov/pub/data/sds/cdr/CDRs/Aerosol_Optical_Thickness/AlgorithmDescription_01B-04.pdf).\n\nImage and data processing by NOAA's National Climatic Data Center.\n\n### Bands\n\n\n**Pixel Size**\n\n11132 meters\n\n**Bands**\n\n| Name | Min | Max | Pixel Size | Description |\n|-------|---------|--------|------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `aot` | -0.19\\* | 4.95\\* | meters | Atmosphere optical thickness; the degree to which aerosols prevent the transmission of light by absorption or scattering of light. A value of 0.01 corresponds to an extremely clean atmosphere, and a value of 0.4 would correspond to a very hazy condition. An average aerosol optical depth for the U.S. is 0.1 to 0.15. |\n\n\\* estimated min or max value\n\n### Terms of Use\n\n**Terms of Use**\n\nThe NOAA CDR Program's official distribution point for CDRs is NOAA's\nNational Climatic Data Center which provides sustained, open access and\nactive data management of the CDR packages and related information in\nkeeping with the United States' open data policies and practices as\ndescribed in the President's Memorandum on \"Open Data Policy\" and pursuant\nto the Executive Order of May 9, 2013, \"Making Open and Machine Readable\nthe New Default for Government Information\". In line with these policies,\nthe CDR data sets are nonproprietary, publicly available, and no\nrestrictions are placed upon their use. For more information, see the\n[Fair Use of NOAA's CDR Data Sets, Algorithms and Documentation](https://www1.ncdc.noaa.gov/pub/data/sds/cdr/CDRs/Aerosol_Optical_Thickness/UseAgreement_01B-04.pdf)\npdf.\n\n### Citations\n\nCitations:\n\n- Zhao, Xuepeng; and NOAA CDR Program: NOAA Climate Data Record (CDR)\n of AVHRR Daily and Monthly Aerosol Optical Thickness (AOT) over Global\n Oceans, Version 4.0. \\[indicate subset used\\]. NOAA National Centers for\n Environmental Information. [doi:10.25921/w3zj-4y48](https://doi.org/10.25921/w3zj-4y48)\n \\[date accessed\\].\n\n### DOIs\n\n- \u003chttps://doi.org/10.25921/w3zj-4y48\u003e\n\n### Explore with Earth Engine\n\n| **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)\n\n### Code Editor (JavaScript)\n\n```javascript\nvar dataset = ee.ImageCollection('NOAA/CDR/AVHRR/AOT/V4')\n .filter(ee.Filter.date('2018-02-01', '2018-03-01'));\nvar aerosolOpticalThickness = dataset.select('aot');\nvar visParams = {\n min: 0.0,\n max: 0.5,\n palette: ['800080', '0000ff', '00ffff', '008000', 'ffff00', 'ff0000'],\n};\nMap.setCenter(-88.6, 26.4, 3);\nMap.addLayer(\n aerosolOpticalThickness, visParams,\n 'Aerosol Optical Thickness');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/NOAA/NOAA_CDR_AVHRR_AOT_V4) \n[NOAA CDR AVHRR AOT: Daily Aerosol Optical Thickness Over Global Oceans, v04](/earth-engine/datasets/catalog/NOAA_CDR_AVHRR_AOT_V4) \nThe NOAA Climate Data Record (CDR) of Aerosol Optical Thickness (AOT) is a collection of global daily 0.1 degree derived data from the PATMOS-x AVHRR level-2b channel 1 (0.63 micron) orbital clear-sky radiance. The aerosol product is generated from AVHRR imagery in cloud-free conditions during daytime over oceans. Due to ... \nNOAA/CDR/AVHRR/AOT/V4, aerosol,atmosphere,atmospheric,avhrr,cdr,daily,noaa,optical,pollution \n1981-01-01T00:00:00Z/2025-06-25T00:00:00Z \n-90 -180 90 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [https://doi.org/10.25921/w3zj-4y48](https://doi.org/https://doi.org/10.25921/w3zj-4y48)\n- [https://doi.org/10.25921/w3zj-4y48](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/NOAA_CDR_AVHRR_AOT_V4)"]]
