NCI Data Collections & Publishing

Page tree

Versions Compared

Old Version 3

changes.mady.by.user Vincent Villani

Saved on

compared with

New Version 4

changes.mady.by.user Vincent Villani

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

Figure 1. Visulisation of the rain rate intensity variable (crr_intensity) from the Convective Rain Rate (CRR) product at 2022-01-01 03:00 UTC

Abstract

Convective Rainfall Rate (CRR) product is a Nowcasting tool that provides information on
convective, and stratiform associated to convection, instantaneous rain rates and hourly
accumulations.

In the processing of the product, CRR uses some calibration analytical functions that have been
calibrated taking as “truth” the radar data.

There are two types of functions:

  • 2-Variable (2-V) function that depends on 10.8IR and (10.8IR - 6.2WV) satellite data
  • 3-Variable (3-V) function that depends on 10.8IR, (10.8IR - 6.2WV) and 0.6VIS-N satellite
    data

The 3-V calibration analytical function gives better results but there are some situations in which it
can’t be used, for instance, during the night time.

The analytical functions have been calibrated using radar data from:

  • Baltic radar network
  • Hungarian radar network
  • Spanish radar network


To take into account the influence of environmental and orographic effects on the precipitation
distribution, some corrections can be applied to the basic CRR value.

The possible corrections arethe moisture correction, the cloud top growth/decaying rates or evolution correction, the cloud top
temperature gradient correction and the orographic correction.

At this stage, the CRR precipitation pattern computed in the previous step is combined with a
precipitation pattern derived through a lightning algorithm.

The output contains information on the instantaneous rain rate in mm/h in each
pixel of the image. The hourly accumulation output gives information about the precipitation
occurred during the last hour.

Information on the corrections applied and the processing status is available on the CRR_QUALITY
and CRR_DATAFLAG outputs respectively.

For further information please view the following documents:

  1. Algorithm Theoretical Basis Document
  2. User Manual
  3. Validation Report

Note: The lightning correction has been tuned to Australian networks and is only applied to the 0N - 50S, 105E - 175E spatial domain.

Format

NetCDF4

Basepath and Filename Template

Base path: /g/data/rv74/satellite-products/arc/der/himawari-ahi/precip/crr/<year>/<month>/<day>/

Filename Template: S_NWC_CRR_<satellite>_HIMA-N-NR_<year><month><day>T<hour><minute>00Z.nc

<satellite>: HIMA08 or HIMA09

Version

Version 2.0: Initial release. Processed using EUMETSAT NWCSAF GEO software, version v2021.1. Input data includes Himawari-AHI data, NOAA's GFS 0.5 degree 6 and 12 hour forecasts, Bureau of Meteorology GAMSSA Sea Surface Temperature and ENGLN lightning data.

License

CC-BY-4.0

Update Frequency

Monthly with 3 month data latency

Temporal extents (YYYY/MM/DD)

2015/07/07 - present (with 3 month data latency)

Spatial Extents

81N ~ 81S, 59E ~ 222E

Note: The lightning correction is only applied to the  0N ~ 50S, 105E ~ 175E spatial domain

Owner

Bureau of Meteorology

Contact

SI-Research-SS@bom.gov.au 

Satellite Science Team, Research, Bureau of Meteorology

Credit

Many thanks to the Japan Meteorological Agency (JMA) for providing Himawari-AHI data and NOAA for providing GFS data.

Convective Rain Rate data derived from satellite imagery processed by the Bureau of Meteorology from Himawari-AHI data provided by the Japan Meteorological Agency using software provided by EUMETSAT NWCSAF.

Metadata Example

netcdf S_NWC_CRR_HIMA08_HIMA-N-NR_20220101T030000Z {

dimensions:

    ny = 5500 ;
    nx = 5500 ;
    pal02_colors = 256 ;
    pal_RGB = 3 ;
    pal01_colors = 256 ;


variables:

    ubyte crr(ny, nx) ;
        crr:long_name = "NWC GEO CRR Convective Rainfall Rate Class" ;
        crr:valid_range = 0UB, 11UB ;
        crr:_FillValue = 255UB ;
        crr:ancillary_variables = "crr_status_flag  crr_conditions crr_quality crr_pal" ;
        crr:coordinates = "lon lat" ;
        crr:flag_values = 0UB, 1UB, 2UB, 3UB, 4UB, 5UB, 6UB, 7UB, 8UB, 9UB, 10UB, 11UB ;
        crr:flag_meanings = "00_02_mm_h 02_1_mm_h 1_2_mm_h 2_3_mm_h 3_5_mm_h 5_7_mm_h 7_10_mm_h 10_15_mm_h 15_20_mm_h 20_30_mm_h 30_50_mm_h 50____mm_h" ;
        crr:grid_mapping = "geostationary" ;


    ushort crr_accum(ny, nx) ;
        crr_accum:long_name = "NWC GEO CRR Convective Hourly Rainfall Accumulation" ;
        crr_accum:scale_factor = 0.1f ;
        crr_accum:add_offset = 0.f ;
        crr_accum:units = "mm" ;
        crr_accum:valid_range = 0US, 500US ;
        crr_accum:_FillValue = 65535US ;
        crr_accum:ancillary_variables = "crr_status_flag  crr_conditions crr_quality crr_intensity_pal" ;
        crr_accum:coordinates = "lon lat" ;
        crr_accum:grid_mapping = "geostationary" ;


    ushort crr_conditions(ny, nx) ;
        crr_conditions:long_name = "Common geophysical and processing conditions" ;
        crr_conditions:valid_range = 1US, 65535US ;
        crr_conditions:_FillValue = 0US ;
        crr_conditions:flag_mask = 1US, 6US, 6US, 6US, 8US, 48US, 48US, 48US, 64US, 128US, 768US, 768US, 768US, 3072US, 3072US, 3072US, 12288US, 12288US, 12288US, 49152US, 49152US, 49152US ;
        crr_conditions:flag_values = 1US, 2US, 4US, 6US, 8US, 16US, 32US, 48US, 64US, 128US, 256US, 512US, 768US, 1024US, 2048US, 3072US, 4096US, 8192US, 12288US, 16384US, 32768US, 49152US ;
        crr_conditions:flag_meanings = "space night day twilight sunglint land sea coast not_used not_used all_satellite_channels_available useful_satellite_channels_missing mandatory_satellite_channels_missing all_NWP_fields_available useful_NWP_fields_missing mandatory_NWP_fields_missing all_product_data_available useful_product_data_missing mandatory_product_data_missing all_auxiliary_data_available useful_auxiliary_data_missing mandatory_auxiliary_data_missing" ;
        crr_conditions:comment = "Common geophysical and processing conditions" ;
        crr_conditions:grid_mapping = "geostationary" ;


    ushort crr_intensity(ny, nx) ;
        crr_intensity:standard_name = "convective_precipitation_rate" ;
        crr_intensity:long_name = "NWC GEO CRR Convective Rainfall Intensity" ;
        crr_intensity:scale_factor = 0.1f ;
        crr_intensity:add_offset = 0.f ;
        crr_intensity:units = "mm/h" ;
        crr_intensity:valid_range = 0US, 500US ;
        crr_intensity:_FillValue = 65535US ;
        crr_intensity:ancillary_variables = "crr_status_flag  crr_conditions crr_quality crr_intensity_pal" ;
        crr_intensity:coordinates = "lon lat" ;
        crr_intensity:grid_mapping = "geostationary" ;


    ubyte crr_intensity_pal(pal02_colors, pal_RGB) ;
        crr_intensity_pal:long_name = "RGB palette for crr_intensity" ;
        crr_intensity_pal:valid_range = 0UB, 255UB ;
        crr_intensity_pal:colormodel = "RGB" ;
        crr_intensity_pal:comment = "Palette applicable to field crr_intensity" ;


    ubyte crr_pal(pal01_colors, pal_RGB) ;
        crr_pal:long_name = "RGB palette for crr" ;
        crr_pal:valid_range = 0UB, 255UB ;
        crr_pal:colormodel = "RGB" ;
        crr_pal:comment = "Palette applicable to field crr" ;


    ushort crr_quality(ny, nx) ;
        crr_quality:long_name = "Common Quality Indicators" ;
        crr_quality:valid_range = 1US, 56US ;
        crr_quality:_FillValue = 0US ;
        crr_quality:flag_mask = 1US, 2US, 4US, 56US, 56US, 56US, 56US ;
        crr_quality:flag_values = 1US, 2US, 4US, 8US, 16US, 24US, 32US ;
        crr_quality:flag_meanings = "nodata internal_consistency temporal_consistency good questionable bad interpolated" ;
        crr_quality:comment = "Common Quality Indicators" ;
        crr_quality:grid_mapping = "geostationary" ;


    ushort crr_status_flag(ny, nx) ;
        crr_status_flag:standard_name = "status_flag" ;
        crr_status_flag:long_name = "Information on specific NWC GEO CRR processing" ;
        crr_status_flag:valid_range = 1US, 4096US ;
        crr_status_flag:_FillValue = 0US ;
        crr_status_flag:flag_mask = 1US, 2US, 4US, 8US, 16US, 32US, 64US, 128US, 256US, 3584US, 3584US, 3584US, 3584US, 4096US ;
        crr_status_flag:flag_values = 1US, 2US, 4US, 8US, 16US, 32US, 64US, 128US, 256US, 512US, 1024US, 1536US, 2048US, 4096US ;
        crr_status_flag:flag_meanings = "humidity_correction_applied evolution_correction_applied gradient_correction_applied parallax_correction_applied orographic_correction_applied solar_data_used lightning_data_used data_filtered data_hole_filled all_bands_for_accumulation_available one_band_for_accumulation_missing several_no_consecutive_bands_for_accumulation_missing several_consecutive_bands_for_accumulation_missing accumulation_quality_flag" ;
        crr_status_flag:coordinates = "lon lat" ;
        crr_status_flag:grid_mapping = "geostationary" ;


    float nx(nx) ;
        nx:standard_name = "projection_x_coordinate" ;
        nx:long_name = "X Georeferenced Coordinate for each pixel count" ;
        nx:units = "m" ;


    float ny(ny) ;
        ny:standard_name = "projection_y_coordinate" ;
        ny:long_name = "Y Georeferenced Coordinate for each pixel count" ;
        ny:units = "m" ;


    float geostationary ;
        geostationary:proj_name = "GEOS141" ;
        geostationary:sweep_angle_axis = "y" ;
        geostationary:false_northing = 0LL ;
        geostationary:grid_mapping_name = "geostationary" ;
        geostationary:false_easting = 0LL ;
        geostationary:satellite_height = 35785863. ;
        geostationary:semi_major_axis = 6378137. ;
        geostationary:semi_minor_axis = 6356752.3 ;
        geostationary:perspective_point_height = 35785863. ;
        geostationary:GeoTransform = -5500000., 2000., 0., 5500000., 0., -2000. ;
        geostationary:longitude_of_projection_origin = 140.7 ;
        geostationary:proj4 = "+proj=geos +lon_0=140.7 +h=35785863 +x_0=0 +y_0=0 +a=6378137 +b=6356752.3 +units=m +no_defs" ;
        geostationary:spatial_ref = "PROJCS[\"unnamed\",GEOGCS[\"unnamed ellipse\",DATUM[\"unknown\",SPHEROID[\"unnamed\",6378137,298.2570248822731]],PRIMEM[\"Greenwich\",0],UNIT[\"degree\",0.0174532925199433]],PROJECTION[\"Geostationary_Satellite\"],PARAMETER[\"central_meridian\",140.7],PARAMETER[\"satellite_height\",35785863],PARAMETER[\"false_easting\",0],PARAMETER[\"false_northing\",0],UNIT[\"Meter\",1]]" ;


// global attributes:
        :Conventions = "CF-1.6" ;
        :title = "NWC GEO Convective Rainfall Rate Product" ;
        :institution = "Bureau of Meteorology" ;
        :source = "NWC/GEO version v2021.1" ;
        :comment = "Copyright 2022, EUMETSAT, All Rights Reserved" ;
        :references = "http://nwc-saf.eumetsat.int" ;
        :contact = "safnwchd@aemet.es" ;
        :summary = "Convective Rainfall Rate Product of the NWC/GEO. Estimation of the precipitation rate associated to convective clouds" ;
        :keywords = "Precipitation Rate, Convection, Rain Rate" ;
        :keywords_vocabulary = "GCMD Science Keywords" ;
        :id = "S_NWC_CRR_HIMA08_HIMA-N-NR_20220101T030000Z.nc" ;
        :naming_authority = "Bureau of Meteorology" ;
        :cdm_data_type = "Image" ;
        :date_created = "2022-12-27T08:54:29Z" ;
        :creator_name = "Bureau of Meteorology" ;
        :creator_url = "www.bom.gov.au" ;
        :creator_email = "SI-Research-SS@bom.gov.au" ;
        :project = "NWC/GEO" ;
        :processing_level = "Level 2" ;
        :time_coverage_start = "2022-01-01T03:00:20Z" ;
        :time_coverage_end = "2022-01-01T03:09:40Z" ;
        :license = "EUMETSAT user policy" ;
        :saf = "NWC/GEO" ;
        :product_name = "CRR" ;
        :product_algorithm_version = "4.0.2" ;
        :satellite_identifier = "HIMA08" ;
        :sub-satellite_longitude = 140.7f ;
        :centre_projection_longitude = 140.7f ;
        :nominal_product_time = "2022-01-01T03:00:00Z" ;
        :region_id = "HIMA-N" ;
        :region_name = "HIMA-N; CENTRE=0N 140.7E; SIZE=5500x5500pix" ;
        :spatial_resolution = 2.f ;
        :cgms_projection = "+proj=geos +coff=2750.500000 +cfac=20466275.000000 +loff=2750.500000 +lfac=20466275.000000 +spp=140.699997 +r_eq=6378.137000 +r_pol=6356.752300 +h=42164.000000" ;
        :gdal_projection = "+proj=geos +a=6378137.000000 +b=6356752.300000 +lon_0=140.699997 +h=35785863.000000 +sweep=y" ;
        :gdal_geotransform_table = -5499996.f, 1999.998f, 0.f, 5499996.f, 0.f, -1999.998f ;
        :gdal_xgeo_up_left = -5499996.f ;
        :gdal_ygeo_up_left = 5499996.f ;
        :gdal_xgeo_low_right = 5499996.f ;
        :gdal_ygeo_low_right = -5499996.f ;
        :product_quality = 73.f ;
        :product_completeness = 76.f ;
        :geospatial_lat_max = 81.04704f ;
        :geospatial_lat_min = -81.04704f ;
        :geospatial_lon_max = 180.f ;
        :geospatial_lon_min = -180.f ;
        :product_version = "2.0" ;
        :history = "Fri Jan 20 06:38:34 2023: ncatted -O -a product_version,global,c,c,2.0 /scratch/er8/vov548/output/nwcsaf_2021.1_h8_reprocessing/crr//S_NWC_CRR_HIMA08_HIMA-N-NR_20220101T030000Z.nc\nFri Jan 20 06:38:22 2023: ncks -O -L 9 --cnk_dmn x,5500 --cnk_dmn y,20 /scratch/er8/vov548/output/nwcsaf_2021.1_h8_compressed/crr/S_NWC_CRR_HIMA08_HIMA-N-NR_20220101T030000Z.nc /scratch/er8/vov548/output/nwcsaf_2021.1_h8_reprocessing/crr//S_NWC_CRR_HIMA08_HIMA-N-NR_20220101T030000Z.nc\nThu Dec 29 01:37:16 2022: ncatted -O -a product_version,global,c,c,2.0 /scratch/er8/vov548/output/nwcsaf_2021.1_h8//S_NWC_CRR_HIMA08_HIMA-N-NR_20220101T030000Z.nc\nThu Dec 29 01:37:04 2022: ncks -O -L 9 --cnk_dmn x,5500 --cnk_dmn y,20 /scratch/er8/vov548/output/nwcsaf_2021.1_h8/S_NWC_CRR_HIMA08_HIMA-N-NR_20220101T030000Z.nc /scratch/er8/vov548/output/nwcsaf_2021.1_h8//S_NWC_CRR_HIMA08_HIMA-N-NR_20220101T030000Z.nc\n2022-12-27T08:54:29Z (null) Product Created by NWC/GEO v2021.1\n2022-12-27T08:54:29Z (null) GEO-CRR-v402 2022-01-01T03:00:00Z /scratch/er8/vov548/ws/nwcsaf_2021.1_h8/install/tmp66z3dl8b/config/safnwc_HIMAN./scratch/er8/vov548/ws/nwcsaf_2021.1_h8/install/tmp66z3dl8b/config/safnwc_CRR.cf4.0.2 /scratch/er8/vov548/ws/nwcsaf_2021.1_h8/install/tmp66z3dl8b/config/safnwc_CRR.cf4.0.2" ;
        :NCO = "netCDF Operators version 4.7.7 (Homepage = http://nco.sf.net, Code = http://github.com/nco/nco)" ;
}