{ "type": "Collection", "id": "GPM_3IMERGDF.07", "stac_version": "1.0.0", "title": "GPM IMERG Final Precipitation L3 1 day 0.1 degree x 0.1 degree V07 (GPM_3IMERGDF) at GES DISC", "description": "\nVersion 07 is the current version of the data set. Older versions will no longer be available and have been superseded by Version 07.\n\nThe Integrated Multi-satellitE Retrievals for GPM (IMERG) IMERG is a NASA product estimating global surface precipitation rates at a high resolution of 0.1° every half-hour beginning 2000. It is part of the joint NASA-JAXA Global Precipitation Measurement (GPM) mission, using the GPM Core Observatory satellite as the standard to combine precipitation observations from an international constellation of satellites using advanced techniques. IMERG can be used for global-scale applications as well as over regions with sparse or no reliable surface observations. The fine spatial and temporal resolution of IMERG data allows them to be accumulated to the scale of the application for increased skill. IMERG has three Runs with varying latencies in response to a range of application needs: rapid-response applications (Early Run, 4-h latency), same/next-day applications (Late Run, 14-h latency), and post-real-time research (Final Run, 3.5-month latency). While IMERG strives for consistency and accuracy, satellite estimates of precipitation are expected to have lower skill over frozen surfaces, complex terrain, and coastal zones. As well, the changing GPM satellite constellation over time may introduce artifacts that affect studies focusing on multi-year changes.\n\nThis dataset is the GPM Level 3 IMERG *Final* Daily 10 x 10 km (GPM_3IMERGDF) derived from the half-hourly GPM_3IMERGHH. The derived result represents the Final estimate of the daily mean precipitation rate in mm/day. The dataset is produced by first computing the mean precipitation rate in (mm/hour) in every grid cell, and then multiplying the result by 24. This minimizes the possible dry bias in versions before \"07\", in the simple daily totals for cells where less than 48 half-hourly observations are valid for the day. The latter under-sampling is very rare in the combined microwave-infrared and rain gauge dataset, variable \"precipitation\", and appears in higher latitudes. Thus, in most cases users of global \"precipitation\" data will not notice any difference. This correction, however, is noticeable in the high-quality microwave retrieval, variable \"MWprecipitation\", where the occurrence of less than 48 valid half-hourly samples per day is very common. The counts of the valid half-hourly samples per day have always been provided as a separate variable, and users of daily data were advised to pay close attention to that variable and use it to calculate the correct precipitation daily rates. Starting with version \"07\", this is done in production to minimize possible misinterpretations of the data. The counts are still provided in the data, but they are only given to gauge the significance of the daily rates, and reconstruct the simple totals if someone wishes to do so. \n\nThe latency of the derived *Final* Daily product depends on the delivery of the IMERG *Final* Half-Hourly product GPM_IMERGHH. Since the latter are delivered in a batch, once per month for the entire month, with 2-3 months latency, so will be the latency for the Final Daily, plus about 24 hours. Thus, e.g. the Dailies for January can be expected to appear no earlier than April 2. \n\n\n\nThe daily mean rate (mm/day) is derived by first computing the mean precipitation rate (mm/hour) in a grid cell for the data day, and then multiplying the result by 24. Thus, for every grid cell we have \n\nPdaily_mean = SUM{Pi * 1[Pi valid]} / Pdaily_cnt * 24, i=[1,Nf]\n\nWhere:\nPdaily_cnt = SUM{1[Pi valid]}\n\nPi - half-hourly input, in (mm/hr)\nNf - Number of half-hourly files per day, Nf=48\n1[.] - Indicator function; 1 when Pi is valid, 0 otherwise\nPdaily_cnt - Number of valid retrievals in a grid cell per day.\n\nGrid cells for which Pdaily_cnt=0, are set to fill value in the Daily files.\nNote that Pi=0 is a valid value.\n\nPdaily_cnt are provided in the data files as variables \"precipitation_cnt\" and \"MWprecipitation_cnt\", for correspondingly the microwave-IR-gauge and microwave-only retrievals. They are only given to gauge the significance of the daily rates, and reconstruct the simple totals if someone wishes to do so. \n\nThere are various ways the daily error could be estimated from the source half-hourly random error (variable \"randomError\"). The daily error provided in the data files is calculated in a fashion similar to the daily mean precipitation rate. First, the mean of the squared half-hourly \"randomError\" for the day is computed, and the resulting (mm^2/hr) is converted to (mm^2/day). Finally, square root is taken to get the result in (mm/day):\n\nPerr_daily = { SUM{ (Perr_i)^2 * 1[Perr_i valid] ) } / Ncnt_err * 24}^0.5, i=[1,Nf]\nNcnt_err = SUM( 1[Perr_i valid] )\n\nwhere:\nPerr_i\t\t- half-hourly input, \"randomError\", (mm/hr)\nPerr_daily\t- Magnitude of the daily error, (mm/day)\nNcnt_err\t\t- Number of valid half-hour error estimates\n\nAgain, the sum of squared \"randomError\" can be reconstructed, and other estimates can be derived using the available counts in the Daily files.\n", "links": [], "stac_extensions": [ "https://stac-extensions.github.io/datacube/v2.2.0/schema.json" ], "collection_concept_id": "C2723754864-GES_DISC", "cube:dimensions": { "time": { "extent": [ "2000-06-01T00:00:00Z", null ], "description": "time", "step": "P1D", "type": "temporal" }, "lon": { "axis": "x", "extent": [ -179.9499969482422, 179.9499969482422 ], "description": "Longitude", "reference_system": 4326, "type": "spatial" }, "lat": { "axis": "y", "extent": [ -89.95, 89.95 ], "description": "Latitude", "reference_system": 4326, "type": "spatial" } }, "cube:variables": { "precipitation": { "type": "data", "description": "Daily mean precipitation rate (combined microwave-IR) estimate. Formerly precipitationCal.", "dimensions": [ "time", "lon", "lat" ], "unit": "mm/day", "attrs": { "units": "mm/day", "long_name": "Daily mean precipitation rate (combined microwave-IR) estimate. Formerly precipitationCal." }, "shape": [ null, 3600, 1800 ], "chunks": [ 1, 3600, 900 ], "renders": "precipitation" }, "precipitation_cnt": { "type": "data", "description": "Count of all valid half-hourly precipitation retrievals for the day", "dimensions": [ "time", "lon", "lat" ], "unit": "count", "attrs": { "units": "count", "long_name": "Count of all valid half-hourly precipitation retrievals for the day" }, "shape": [ null, 3600, 1800 ], "chunks": [ 1, 3600, 900 ] }, "precipitation_cnt_cond": { "type": "data", "description": "Count of half-hourly precipitation retrievals for the day where precipitation is at least 0.01 mm/hr", "dimensions": [ "time", "lon", "lat" ], "unit": "count", "attrs": { "units": "count", "long_name": "Count of half-hourly precipitation retrievals for the day where precipitation is at least 0.01 mm/hr" }, "shape": [ null, 3600, 1800 ], "chunks": [ 1, 3600, 900 ] }, "MWprecipitation": { "type": "data", "description": "Daily mean High Quality precipitation rate from all available microwave sources. Formerly HQprecipitation.", "dimensions": [ "time", "lon", "lat" ], "unit": "mm/day", "attrs": { "units": "mm/day", "long_name": "Daily mean High Quality precipitation rate from all available microwave sources. Formerly HQprecipitation." }, "shape": [ null, 3600, 1800 ], "chunks": [ 1, 3600, 900 ], "renders": "MWprecipitation" }, "MWprecipitation_cnt": { "type": "data", "description": "Count of all valid half-hourly MWprecipitation retrievals for the day", "dimensions": [ "time", "lon", "lat" ], "unit": "count", "attrs": { "units": "count", "long_name": "Count of all valid half-hourly MWprecipitation retrievals for the day" }, "shape": [ null, 3600, 1800 ], "chunks": [ 1, 3600, 900 ] }, "MWprecipitation_cnt_cond": { "type": "data", "description": "Count of half-hourly MWprecipitation retrievals for the day where precipitation is at least 0.01 mm/hr", "dimensions": [ "time", "lon", "lat" ], "unit": "count", "attrs": { "units": "count", "long_name": "Count of half-hourly MWprecipitation retrievals for the day where precipitation is at least 0.01 mm/hr" }, "shape": [ null, 3600, 1800 ], "chunks": [ 1, 3600, 900 ] }, "randomError": { "type": "data", "description": "Root-mean-square error estimate for combined microwave-IR daily precipitation rate", "dimensions": [ "time", "lon", "lat" ], "unit": "mm/day", "attrs": { "units": "mm/day", "long_name": "Root-mean-square error estimate for combined microwave-IR daily precipitation rate" }, "shape": [ null, 3600, 1800 ], "chunks": [ 1, 3600, 900 ], "renders": "randomError" }, "randomError_cnt": { "type": "data", "description": "Count of valid half-hourly randomError retrievals for the day", "dimensions": [ "time", "lon", "lat" ], "unit": "count", "attrs": { "units": "count", "long_name": "Count of valid half-hourly randomError retrievals for the day" }, "shape": [ null, 3600, 1800 ], "chunks": [ 1, 3600, 900 ] }, "probabilityLiquidPrecipitation": { "type": "data", "description": "Probability of liquid precipitation estimated with a diagnostic parameterization using ancillary data. 0=missing values; 1=likely solid; 100=likely liquid or no precipitation. Screen by positive precipitation or precipitation_cnt_cond to locate meaningful probabilities.", "dimensions": [ "time", "lon", "lat" ], "unit": "percent", "attrs": { "units": "percent", "long_name": "Probability of liquid precipitation", "description": "Probability of liquid precipitation estimated with a diagnostic parameterization using ancillary data. 0=missing values; 1=likely solid; 100=likely liquid or no precipitation. Screen by positive precipitation or precipitation_cnt_cond to locate meaningful probabilities." }, "shape": [ null, 3600, 1800 ], "chunks": [ 1, 3600, 900 ] }, "time_bnds": { "type": "data", "dimensions": [ "time", "nv" ], "attrs": {}, "shape": [ null, 2 ], "chunks": [ 1, 2 ] } }, "renders": { "precipitation": { "title": "Renders configuration for precipitation", "resampling": "average", "colormap_name": "jet", "rescale": [ [ 0, 48 ] ], "backend": "xarray" }, "MWprecipitation": { "title": "Renders configuration for MWprecipitation", "resampling": "average", "colormap_name": "cfastie", "rescale": [ [ 0, 50 ] ], "backend": "xarray" }, "randomError": { "title": "Renders configuration for randomError", "resampling": "average", "colormap_name": "reds", "rescale": [ [ 0, 17469 ] ], "backend": "xarray" } }, "extent": { "spatial": { "bbox": [ [ -180, -90, 180, 90 ] ] }, "temporal": { "interval": [ [ "2000-06-01T00:00:00Z", null ] ] } }, "license": "CC0-1.0", "providers": [ { "name": "NASA/GSFC/SED/ESD/GCDC/GESDISC", "description": "Goddard Earth Sciences Data and Information Services Center (formerly Goddard DAAC), Global Change Data Center, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA", "roles": [], "url": "https://disc.gsfc.nasa.gov/" } ] }