netcdf nsavisstpxn15minnisX1.c1.20021231.222800 { dimensions: time = 697 ; variables: int base_time ; base_time:long_name = "Base time in epoch" ; base_time:units = "seconds since 1970-1-1 0:00:00 GMT" ; base_time:string = "2002-12-31, 00:00:00 GMT" ; double time_offset ; time_offset:long_name = "Time offset from base_time" ; time_offset:units = "seconds since 2002-12-31, 00:00:00 GMT" ; time_offset:NOTE1 = "This is the time of the first pixel in subsected domain" ; time_offset:NOTE2 = "If > 86400, subtract 86400 from time_offset and add 86400 to base_time" ; float time(time) ; time:long_name = "Time offset from midnight" ; time:units = "seconds since 2002-12-31, 00:00:00 GMT" ; time:NOTE1 = "This is time of the scan line in subsected domain" ; time:NOTE2 = "If > 86400, subtract 86400 from time and add 86400 to base_time" ; float latitude(time) ; latitude:long_name = "North latitude" ; latitude:units = "degree_N" ; latitude:valid_min = -90.f ; latitude:valid_max = 90.f ; latitude:comment = "The image navigation has been improved relative to what is present in a NOAA CLASS AVHRR Level 1B GAC file, see C-ATBD for description" ; float longitude(time) ; longitude:long_name = "East longitude" ; longitude:units = "degree_E" ; longitude:valid_min = -180.f ; longitude:valid_max = 180.f ; longitude:comment = "The image navigation has been improved relative to what is present in a NOAA CLASS AVHRR Level 1B GAC file, see C-ATBD for description" ; float reflectance_vis(time) ; reflectance_vis:long_name = "Visible reflectance (0.63 um)" ; reflectance_vis:units = "unitless" ; reflectance_vis:valid_min = 0.f ; reflectance_vis:valid_max = 12.5f ; float reflectance_vis86(time) ; reflectance_vis86:long_name = "Visible reflectance (0.86 um)" ; reflectance_vis86:units = "unitless" ; reflectance_vis86:valid_min = 0.f ; reflectance_vis86:valid_max = 12.5f ; float reflectance_nir(time) ; reflectance_nir:long_name = "Near Infrared reflectance (1.61 um)" ; reflectance_nir:units = "unitless" ; reflectance_nir:valid_min = 0.f ; reflectance_nir:valid_max = 12.5f ; float temperature_sir(time) ; temperature_sir:long_name = "Solar Infrared temperature (3.75 um)" ; temperature_sir:units = "K" ; temperature_sir:valid_min = 160.f ; temperature_sir:valid_max = 340.f ; float temperature_ir(time) ; temperature_ir:long_name = "Infrared Channel temperature (10.8 um)" ; temperature_ir:units = "K" ; temperature_ir:valid_min = 160.f ; temperature_ir:valid_max = 340.f ; float temperature_sw(time) ; temperature_sw:long_name = "Split-Window Channel temperature (12.0 um)" ; temperature_sw:units = "K" ; temperature_sw:valid_min = 160.f ; temperature_sw:valid_max = 340.f ; float broadband_shortwave_albedo(time) ; broadband_shortwave_albedo:long_name = "Broadband SW albedo" ; broadband_shortwave_albedo:units = "%" ; broadband_shortwave_albedo:valid_min = 0.f ; broadband_shortwave_albedo:valid_max = 150.f ; float broadband_longwave_flux(time) ; broadband_longwave_flux:long_name = "Broadband LW flux" ; broadband_longwave_flux:units = "W/m^2" ; broadband_longwave_flux:valid_min = 0.f ; broadband_longwave_flux:valid_max = 500.f ; int cloud_phase(time) ; cloud_phase:long_name = "Cloud phase" ; cloud_phase:units = "unitless" ; cloud_phase:value_0 = "clear over snow/ice" ; cloud_phase:value_1 = "water" ; cloud_phase:value_2 = "ice" ; cloud_phase:value_3 = "no retrieval" ; cloud_phase:value_4 = "clear" ; cloud_phase:value_5 = "bad retrieval" ; cloud_phase:value_6 = "suspected water" ; cloud_phase:value_7 = "suspected ice" ; cloud_phase:valid_min = 0 ; cloud_phase:valid_max = 7 ; float visible_optical_depth(time) ; visible_optical_depth:long_name = "Cloud optical depth" ; visible_optical_depth:units = "unitless" ; visible_optical_depth:valid_min = 0.f ; visible_optical_depth:valid_max = 150.f ; float effective_radius(time) ; effective_radius:long_name = "Effective particle radius" ; effective_radius:units = "um" ; effective_radius:valid_min = 0.f ; effective_radius:valid_max = 150.f ; float liquid_water_path(time) ; liquid_water_path:long_name = "Liquid or Ice Water Path" ; liquid_water_path:units = "g/m^2" ; liquid_water_path:value_1 = "NOTE: If phase is 1 or 6 (water), this is Liquid Water Path. It was calculated from a formula: liquid_water_path=0.6667*optical_depth*effective_radius" ; liquid_water_path:value_2 = "NOTE: If phase is 2 or 7 (ice), this is Ice Water Path. It was calculated from a formula: ice_water_path=optical_depth*(0.601*effective_radius - 0.232)" ; liquid_water_path:valid_min = 0.f ; liquid_water_path:valid_max = 6000.f ; float cloud_effective_temperature(time) ; cloud_effective_temperature:long_name = "Effective cloud temperature" ; cloud_effective_temperature:units = "K" ; cloud_effective_temperature:valid_min = 160.f ; cloud_effective_temperature:valid_max = 340.f ; float cloud_top_pressure(time) ; cloud_top_pressure:long_name = "Cloud top pressure" ; cloud_top_pressure:units = "hPa" ; cloud_top_pressure:valid_min = 0.f ; cloud_top_pressure:valid_max = 1050.f ; float cloud_effective_pressure(time) ; cloud_effective_pressure:long_name = "Effective cloud pressure" ; cloud_effective_pressure:units = "hPa" ; cloud_effective_pressure:valid_min = 0.f ; cloud_effective_pressure:valid_max = 1050.f ; float cloud_bottom_pressure(time) ; cloud_bottom_pressure:long_name = "Cloud bottom pressure" ; cloud_bottom_pressure:units = "hPa" ; cloud_bottom_pressure:valid_min = 0.f ; cloud_bottom_pressure:valid_max = 1050.f ; float cloud_top_height(time) ; cloud_top_height:long_name = "Cloud top height" ; cloud_top_height:units = "km" ; cloud_top_height:valid_min = 0.f ; cloud_top_height:valid_max = 25.f ; float cloud_effective_height(time) ; cloud_effective_height:long_name = "Cloud effective height" ; cloud_effective_height:units = "km" ; cloud_effective_height:valid_min = 0.f ; cloud_effective_height:valid_max = 25.f ; float cloud_bottom_height(time) ; cloud_bottom_height:long_name = "Cloud bottom height" ; cloud_bottom_height:units = "km" ; cloud_bottom_height:valid_min = 0.f ; cloud_bottom_height:valid_max = 25.f ; float solar_zenith_angle(time) ; solar_zenith_angle:long_name = "Solar zenith angle" ; solar_zenith_angle:units = "degree" ; solar_zenith_angle:valid_min = 0.f ; solar_zenith_angle:valid_max = 180.f ; float viewing_zenith_angle(time) ; viewing_zenith_angle:long_name = "Viewing zenith angle" ; viewing_zenith_angle:units = "degree" ; viewing_zenith_angle:valid_min = 0.f ; viewing_zenith_angle:valid_max = 90.f ; // global attributes: :NetCDF_Version = "netCDF 4.0.1" ; :Title = "Pixel-level cloud products subsetted from V1 NASA LaRC AVHRR Cloud and Clear-Sky Radiation Property Dataset" ; :source = "NASA Langley Research Center" ; :version = "V4.1" ; :date = "VISST processed on 2015-09-03T15:37:29Z" ; :facility_id = "X1" ; :site_id = "nsa" ; :location = "nsa" ; :data_level = "c1" ; :missing_value = "-9999." ; :zeb_platform = "nsavisstpxn15minnisX1.c1" ; :history = "created by user mk on machine ssai at Tue May 19 02:32:21 2020 UTC, using IDL 8.5.1" ; :input_files = "NOAA-15" ; :resolution = "4km" ; :reflectance_vis_note1 = "effective_wavelength_visst = 0.63 um" ; :reflectance_vis_note2 = "spectral_width_instrument = 0.58 um - 0.68 um" ; :temperature_sir_note1 = "effective_wavelength_visst = 3.75 um" ; :temperature_sir_note2 = "spectral_width_instrument = 3.55 um - 3.93 um" ; :temperature_ir_note1 = "effective_wavelength_visst = 10.8 um" ; :temperature_ir_note2 = "spectral_width_instrument = 10.3 um - 11.3 um" ; :temperature_sw_note1 = "effective_wavelength_visst = 12.0 um" ; :temperature_sw_note2 = "spectral_width_instrument = 11.5 - 12.5 um" ; :longwave_NB_BB_correlation = "The LW NB-BB correlation is given by Mbb=a+b*Mnb+c*Mnb*Mnb+dMnb*ln(colRH), where Mbb is the BB OLR(Wm-2), Mnb is the NB flux(Wm-2um-1), and colRH is the column weighted relative humidity(%) above the radiating surface. The coefficients are, for land night a=71.0942,b= 6.1761,c= -0.0179,d= -0.3311 and day a= 80.6432 b= 5.3019 c= -0.0154,d= -0.2242; ocean night a= 85.1333,b= 5.1444,c= -0.0077,d= -0.2898 ; day a= 97.4948,b= 4.7198,c= -0.0042,d= -0.3003; snow night: a= 83.4691,b= 5.5936,c= -0.0154,d= -0.3141; day: a= 79.3048,b= 6.0833,c= -0.0342,d= -0.2033. The fit was derived from Dec08 NOAA-18 AVHRR/CERES-Aqua Ed3A fluxes covering the globe. For land, the day RMS is 8.62 Wm-2 (3.3%), night is 7.72 Wm-2 (3.2%); for ocean, day 7.26 Wm-2 (3.0%), and night 7.30 Wm-2 (3.0%); for snow, day 7.01 Wm-2 (3.55%), and night 5.89 Wm-2 (3.3%). A third order fit was also applied to eliminate low and high end biases. The CERES limb-darkening function is used to convert NB radiance to flux. These fluxes are preliminary. REFERENCE: Minnis, P., K. Bedka, Q. Trepte, C. R. Yost, S. T. Bedka, B. Scarino, K. Khlopenkov, and M. M. Khaiyer, 2016: A consistent long-term cloud and clear-sky radiation property dataset from the Advanced Very High Resolution Radiometer (AVHRR). Climate Algorithm Theoretical Basis Document (C-ATBD), CDRP-ATBD-0826 Rev 1 AVHRR Cloud Properties - NASA, NOAA CDR Program, 19 September, 159 pp., DOI:10.789/V5HT2M8T." ; :shortwave_NB_BB_correlation = "The shortwave narrowband to broadband correlation is given by Abb = a + b*Anb + c*Anb*Anb + d*ln(1/cos (SZA)), where Abb is the broadband albedo (fraction), Anb is the narrowband albedo (fraction) and SZA is the solar zenith angle (deg). The coefficients are, for land: a= 0.0731,b= 0.5919,c= 0.1337,d= 0.0231; ocean: a= 0.0207,b= 0.7785,c= -0.0528,d= 0.0491; snow: a= -0.0103,b= 1.0847,c= -0.3922,d= 0.0112. The relationship was derived from global Dec08 NOAA-18 AVHRR/CERES-Aqua Ed3A fluxes and has a 0.0232 (9.0%) ocean albedo rms, a 0.0267 (9.3%) land albedo rms, and a 0.0394 (7.0%) snow albedo rms. These albedoes are preliminary. REFERENCE: Minnis, P., K. Bedka, Q. Trepte, C. R. Yost, S. T. Bedka, B. Scarino, K. Khlopenkov, and M. M. Khaiyer, 2016: A consistent long-term cloud and clear-sky radiation property dataset from the Advanced Very High Resolution Radiometer (AVHRR). Climate Algorithm Theoretical Basis Document (C-ATBD), CDRP-ATBD-0826 Rev 1 AVHRR Cloud Properties - NASA, NOAA CDR Program, 19 September, 159 pp., DOI:10.789/V5HT2M8T. " ; :visible_ch1_calibration = "The NOAA-15 AVHRR visible calibration equation is Rad(0.65um) = (g0 + g1*d + g2*d*d)*(C-C0), where g0=0.6416, g1=-0.2540e-5, g2=0.2690e-9, C= visible channel count, C0=is the visible channel offset (38.0), d is the number of days since reference. REFERENCE1: Bhatt,R., D.R. Doelling, B.R. Scarino, A.Gopalan, C.O.Haney, P.Minnis, K.M. Bedka, 2016: A Consistent AVHRR Visible Calibration Record Based on Multiple Methods Applicable for the NOAA Degrading Orbits. Part I: Methodology,Journal of Atmospheric and Oceanic Technology, Vol. 33, No. 11 (DOI: http://dx.doi.org/10.1175/JTECH-D-16-0044.1); REFERENCE2: Doelling,D.R., R. Bhatt, B.R. Scarino, A.Gopalan, C.O. Haney, P.Minnis, K.M. Bedka, A Consistent AVHRR Visible Calibration Record Based on Multiple Methods Applicable for the NOAA Degrading Orbits. Part II: Validation, Journal of Atmospheric and Oceanic Technology, Vol. 33, No. 11 (DOI: http://dx.doi.org/10.1175/JTECH-D-16-0042.1)" ; :visible_ch2_calibration = "The NOAA-15 AVHRR visible calibration equation is Rad(0.86um) = (g0 + g1*d + g2*d*d)*(C-C0), where g0=0.4583, g1=0.5530e-5, g2=-0.9250e-9, C= visible channel count, C0=is the visible channel offset (38.7), d is the number of days since reference. REFERENCE1: Bhatt,R., D.R. Doelling, B.R. Scarino, A.Gopalan, C.O.Haney, P.Minnis, K.M. Bedka, 2016: A Consistent AVHRR Visible Calibration Record Based on Multiple Methods Applicable for the NOAA Degrading Orbits. Part I: Methodology,Journal of Atmospheric and Oceanic Technology, Vol. 33, No. 11 (DOI: http://dx.doi.org/10.1175/JTECH-D-16-0044.1); REFERENCE2: Doelling,D.R., R. Bhatt, B.R. Scarino, A.Gopalan, C.O. Haney, P.Minnis, K.M. Bedka, A Consistent AVHRR Visible Calibration Record Based on Multiple Methods Applicable for the NOAA Degrading Orbits. Part II: Validation, Journal of Atmospheric and Oceanic Technology, Vol. 33, No. 11 (DOI: http://dx.doi.org/10.1175/JTECH-D-16-0042.1)" ; :IR_calibration = "The NOAA-15 AVHRR calibration was based on the nominal equations used in Mcidas." ; :VISST = "NASA Langley cloud and radiation products are produced using VISST (Visible Infrared Solar-infrared Split-Window Technique), SIST (Solar-infrared Infrared Split-Window Technique) and SINT (Solar-infrared Infrared Near-Infrared Technique), an algorithm suite collectively called SatCORPS (Satellite Cloud Observations and Radiative Property retrieval System). SatCORPS uses AVHRR channels to detect clouds, retrieve cloud macro- and micro-physical properties, and also retrieve temperature and radiation properties for clear sky pixels. Atmospheric profiles input to SatCORPS are obtained from MERRA. REFERENCE: Minnis, P., K. Bedka, Q. Trepte, C. R. Yost, S. T. Bedka, B. Scarino, K. Khlopenkov, and M. M. Khaiyer, 2016: A consistent long-term cloud and clear-sky radiation property dataset from the Advanced Very High Resolution Radiometer (AVHRR). Climate Algorithm Theoretical Basis Document (C-ATBD), CDRP-ATBD-0826 Rev 1 AVHRR Cloud Properties - NASA, NOAA CDR Program, 19 September, 159 pp., DOI:10.789/V5HT2M8T." ; :DATA_VERSION_NOTE = "This file includes retrievals of cloud and clear-sky radiation properties for a subsetted area of a swath represented within a single AVHRR Global Area Coverage Level 1B file acquired from the NOAA CLASS. Selected parameters over this domain have been subsetted from part of Version 1.0 of a cloud and clear-sky radiation Climate Data Record produced at the NASA Langley Research Center for the full historical AVHRR time series, which was sponsored by the NOAA Climate Data Records Program described at http://www.ncdc.noaa.gov/cdr/index.html. Not all parameters within this dataset are considered CDR-quality; consult C-ATBD for further information. This data may be reprocessed in the future and replaced. " ; :General_comment = "This dataset is part of ongoing research projects. Users of the data for research leading to conference-level or peer-reviewed publications should contact the developer of the AVHRR cloud dataset, Mr. Kristopher Bedka (kristopher.m.bedka@nasa.gov), and the SatCORPS P.I. for ARM, Dr. William Smith Jr. (william.l.smith@nasa.gov), before publishing papers that include this data. The source of the data should be properly acknowledged and/or co-authorship should be offered depending on the level of documentation and contribution of the particular dataset. For any derived cloud, icing, and radiation products, it is in the best interest of individual researchers who use these datasets to ensure that they are using the latest and highest quality products available. Either Dr. Smith or other group members can provide the proper references, caveats, or level of participation needed for any given request." ; }