M2T1NXRAD（或 tavg1_2d_rad_Nx）是 Modern-Era Retrospective analysis for Research and Applications 版本 2 (MERRA-2) 中的每小时时间平均数据集合。此集合包含辐射诊断变量，例如地表反照率、云面积分数、云内光学厚度、地表入射短波通量（即太阳辐射）、地表净向下短波通量和 TOA（大气层顶部）的上行长波通量（即 TOA 的出射长波辐射 [OLR]）。数据字段的时间戳为从 00:30 UTC 开始的小时的中心时间，例如：00:30、01:30、...、23:30（世界协调时间）。
[null,null,[],[[["\u003cp\u003eThe NASA/GSFC/MERRA/rad/2 dataset provides hourly time-averaged radiation diagnostics from the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2).\u003c/p\u003e\n"],["\u003cp\u003eThis dataset includes measurements such as surface albedo, cloud area fraction, optical thickness, shortwave flux, and longwave flux.\u003c/p\u003e\n"],["\u003cp\u003eData is available from 1980 to near-present with a latency of approximately 3 weeks after the end of a month and is provided at a spatial resolution of 55,000 - 69,375 meters.\u003c/p\u003e\n"],["\u003cp\u003eNASA promotes open sharing of this data with research, industry, academia, and the public.\u003c/p\u003e\n"],["\u003cp\u003eThe data is easily accessible through Google Earth Engine using the provided Earth Engine Snippet.\u003c/p\u003e\n"]]],["The NASA/MERRA-2 dataset (M2T1NXRAD) provides hourly, time-averaged radiation diagnostics from 1980 to 2025, with a ~3-week latency. Data includes surface albedo, cloud fractions, optical thickness, and shortwave/longwave fluxes. It is produced by NASA GMAO using GEOS model version 5.12.4. Data is accessible via Google Earth Engine with specific bands available like ALBEDO, CLDHGH, SWGDN and more. Pixel size is 69375x55000 meters.\n"],null,["Dataset Availability\n: 1980-01-01T00:00:00Z--2025-08-01T23:00:00Z\n\nDataset Provider\n:\n\n\n [NASA/MERRA](https://gmao.gsfc.nasa.gov/reanalysis/MERRA-2/)\n\nCadence\n: 1 Hour\n\nTags\n:\n[albedo](/earth-engine/datasets/tags/albedo) [atmosphere](/earth-engine/datasets/tags/atmosphere) [climate](/earth-engine/datasets/tags/climate) [emissivity](/earth-engine/datasets/tags/emissivity) [merra](/earth-engine/datasets/tags/merra) [shortwave](/earth-engine/datasets/tags/shortwave) [temperature](/earth-engine/datasets/tags/temperature) \n\nDescription \nM2T1NXRAD (or tavg1_2d_rad_Nx) is an hourly time-averaged data\ncollection in Modern-Era Retrospective analysis for Research and\nApplications version 2 (MERRA-2). This collection consists of radiation\ndiagnostics, such as surface albedo, cloud area fraction, in cloud\noptical thickness, surface incoming shortwave flux (i.e. solar\nradiation), surface net downward shortwave flux, and upwelling longwave\nflux at TOA (top of atmosphere) (i.e. outgoing longwave radiation (OLR)\nat TOA). The data field is time-stamped with the central time of an hour\nstarting from 00:30 UTC, e.g.: 00:30, 01:30, ... , 23:30 UTC.\n\nMERRA-2 is the latest version of global atmospheric reanalysis for the\nsatellite era produced by NASA Global Modeling and Assimilation Office\n(GMAO) using the Goddard Earth Observing System Model (GEOS) version\n5.12.4. The dataset covers the period of 1980-present with the latency\nof \\~3 weeks after the end of a month.\n\nBands\n\n\n**Pixel Size**\n\n69375 meters\n\n\n**Y Pixel Size**\n\n55000 meters\n\n**Bands**\n\n| Name | Units | Min | Max | Pixel Size | Description |\n|---------------|--------|-------------|------------|------------|-----------------------------------------------------------------------|\n| `ALBEDO` | | 0.01\\* | 0.898471\\* | meters | Surface albedo |\n| `ALBNIRDF` | | 0.017455\\* | 0.820016\\* | meters | Surface albedo for near infrared diffuse |\n| `ALBNIRDR` | | 0.018709\\* | 0.82001\\* | meters | Surface albedo for near infrared beam |\n| `ALBVISDF` | | 0.016788\\* | 0.959771\\* | meters | Surface albedo for visible diffuse |\n| `ALBVISDR` | | 0.01853\\* | 0.959762\\* | meters | Surface albedo for visible beam |\n| `CLDHGH` | | 0\\* | 0.999236\\* | meters | Cloud area fraction for high clouds |\n| `CLDLOW` | | 0\\* | 0.999997\\* | meters | Cloud area fraction for low clouds |\n| `CLDMID` | | 0\\* | 0.998779\\* | meters | Cloud area fraction for middle clouds |\n| `CLDTOT` | | 0\\* | 1\\* | meters | Total cloud area fraction |\n| `EMIS` | | 0.943074\\* | 0.999993\\* | meters | Surface emissivity |\n| `LWGABCLRCLN` | W/m\\^2 | 41.1408\\* | 458.523\\* | meters | Surface absorbed longwave radiation assuming clear sky and no aerosol |\n| `LWGABCLR` | W/m\\^2 | 41.1414\\* | 465.929\\* | meters | Surface absorbed longwave radiation assuming clear sky |\n| `LWGAB` | W/m\\^2 | 41.1446\\* | 482.398\\* | meters | Surface absorbed longwave radiation |\n| `LWGEM` | W/m\\^2 | 67.5297\\* | 630.29\\* | meters | Longwave flux emitted from surface |\n| `LWGNTCLRCLN` | W/m\\^2 | -248.748\\* | 61.0736\\* | meters | Surface net downward longwave flux assuming clear sky and no aerosol |\n| `LWGNTCLR` | W/m\\^2 | -248.653\\* | 62.2794\\* | meters | Surface net downward longwave flux assuming clear sky |\n| `LWGNT` | W/m\\^2 | -268.862\\* | 77.255\\* | meters | Surface net downward longwave flux |\n| `LWTUPCLRCLN` | W/m\\^2 | 80.6768\\* | 372.229\\* | meters | Upwelling longwave flux at TOA assuming clear sky and no aerosol |\n| `LWTUPCLR` | W/m\\^2 | 80.6768\\* | 372.229\\* | meters | Upwelling longwave flux at TOA assuming clear sky |\n| `LWTUP` | W/m\\^2 | 80.6506\\* | 370.868\\* | meters | Upwelling longwave flux at TOA |\n| `SWGDNCLR` | W/m\\^2 | -0.008217\\* | 1155.5\\* | meters | Surface incoming shortwave flux assuming clear sky |\n| `SWGDN` | W/m\\^2 | 0\\* | 1127.49\\* | meters | Surface incoming shortwave flux |\n| `SWGNTCLN` | W/m\\^2 | 0\\* | 1088.42\\* | meters | Surface net downward shortwave flux assuming no aerosol |\n| `SWGNTCLRCLN` | W/m\\^2 | -3.2e-05\\* | 1088.42\\* | meters | Surface net downward shortwave flux assuming clear sky and no aerosol |\n| `SWGNTCLR` | W/m\\^2 | -0.001333\\* | 1083.95\\* | meters | Surface net downward shortwave flux assuming clear sky |\n| `SWGNT` | W/m\\^2 | 0\\* | 1083.95\\* | meters | Surface net downward shortwave flux |\n| `SWTDN` | W/m\\^2 | 0\\* | 1404.28\\* | meters | TOA incoming shortwave flux |\n| `SWTNTCLN` | W/m\\^2 | 0\\* | 1315.89\\* | meters | TOA net downward shortwave flux assuming no aerosol |\n| `SWTNTCLRCLN` | W/m\\^2 | 0\\* | 1317.5\\* | meters | TOA net downward shortwave flux assuming clear sky and no aerosol |\n| `SWTNTCLR` | W/m\\^2 | 0\\* | 1316.5\\* | meters | TOA net downward shortwave flux assuming clear sky |\n| `SWTNT` | W/m\\^2 | 0\\* | 1313.33\\* | meters | TOA net downward shortwave flux |\n| `TAUHGH` | | 0\\* | 142.188\\* | meters | In cloud optical thickness of high clouds(export) |\n| `TAULOW` | | 0\\* | 318.218\\* | meters | In cloud optical thickness of low clouds |\n| `TAUMID` | | 0\\* | 252.995\\* | meters | In cloud optical thickness of middle clouds |\n| `TAUTOT` | | 0\\* | 348.125\\* | meters | In cloud optical thickness of all clouds |\n| `TS` | K | 185.73\\* | 328.864\\* | meters | Surface skin temperature |\n\n\\* estimated min or max value\n\nTerms of Use\n\n**Terms of Use**\n\nNASA promotes the full and open sharing of all data with research and\napplications communities, private industry, academia, and the general\npublic.\n\nExplore with Earth Engine **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\nCode Editor (JavaScript) \n\n```javascript\nvar dataset = ee.ImageCollection('NASA/GSFC/MERRA/rad/2')\n .filter(ee.Filter.date('2022-02-01', '2022-02-02')).first();\nvar surface_albedo = dataset.select('ALBEDO');\nvar saVis = {\n min: -0.428147,\n max: 0.833350,\n palette: ['001137', '01abab', 'e7eb05', '620500']\n};\nMap.setCenter(-95, 39, 2);\nMap.addLayer(surface_albedo, saVis, 'Surface albedo');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/NASA/NASA_GSFC_MERRA_rad_2) \n[MERRA-2 M2T1NXRAD: Radiation Diagnostics V5.12.4](/earth-engine/datasets/catalog/NASA_GSFC_MERRA_rad_2) \nM2T1NXRAD (or tavg1_2d_rad_Nx) is an hourly time-averaged data collection in Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2). This collection consists of radiation diagnostics, such as surface albedo, cloud area fraction, in cloud optical thickness, surface incoming shortwave flux (i.e. solar radiation), surface net downward shortwave flux, and ... \nNASA/GSFC/MERRA/rad/2, albedo,atmosphere,climate,emissivity,merra,shortwave,temperature \n1980-01-01T00:00:00Z/2025-08-01T23:00:00Z \n-90 -180 90 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [](https://doi.org/https://gmao.gsfc.nasa.gov/reanalysis/MERRA-2/)\n- [](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/NASA_GSFC_MERRA_rad_2)"]]
