netcdf sgpvisstpx04g15v4minnisX1.c1.20121231.011500 { dimensions: time = UNLIMITED ; // (2517588 currently) index = 36 ; variables: int base_time ; base_time:string = "2012-12-31, 00:00:00 GMT" ; base_time:long_name = "base time in epoch" ; base_time:units = "seconds since 1970-1-1 0:00:00 GMT" ; double time_offset(time) ; time_offset:long_name = "Time offset from base_time" ; time_offset:units = "seconds since 2012-12-31 00:00:00 GMT" ; double time(time) ; time:long_name = "Time offset from midnight" ; time:units = "seconds since 2012-12-31 00:00:00 GMT" ; float image_times(index) ; image_times:long_name = "Image times offset from base time" ; image_times:units = "seconds since 2012-12-31 00:00:00 GMT" ; float image_start(index) ; image_start:long_name = "Image start index" ; image_start:usage = "Images are merged together. Individual images can be extracted using the image index fields as in the following IDL example for given image n:\n", "rv = reflectance_vis(image_start(n-1):image_start(n-1)+image_numpix(n-1)-1)" ; float image_numpix(index) ; image_numpix:long_name = "Number of pixels for each image" ; float latitude(time) ; latitude:valid_min = -90.f ; latitude:valid_max = 90.f ; latitude:long_name = "north latitude" ; latitude:units = "deg" ; float longitude(time) ; longitude:valid_min = -180.f ; longitude:valid_max = 180.f ; longitude:long_name = "east longitude" ; longitude:units = "deg" ; float reflectance_vis(time) ; reflectance_vis:valid_min = 0.f ; reflectance_vis:valid_max = 1.6f ; reflectance_vis:long_name = "Visible reflectance (0.65 um)" ; reflectance_vis:units = "unitless" ; float reflectance_nir(time) ; reflectance_nir:valid_min = 0.f ; reflectance_nir:valid_max = 1.6f ; reflectance_nir:long_name = "Near Infrared reflectance (1.6 um)" ; reflectance_nir:units = "unitless" ; float temperature_sir(time) ; temperature_sir:valid_min = 160.f ; temperature_sir:valid_max = 340.f ; temperature_sir:long_name = "Solar Infrared temperature (3.9 um)" ; temperature_sir:units = "K" ; float temperature_ir(time) ; temperature_ir:valid_min = 160.f ; temperature_ir:valid_max = 340.f ; temperature_ir:long_name = "Infrared Channel temperature (10.8 um)" ; temperature_ir:units = "K" ; float temperature_sw(time) ; temperature_sw:valid_min = 160.f ; temperature_sw:valid_max = 340.f ; temperature_sw:long_name = "Split-Window Channel temperature (11.9 um)" ; temperature_sw:units = "K" ; float broadband_shortwave_albedo(time) ; broadband_shortwave_albedo:valid_min = 0.f ; broadband_shortwave_albedo:valid_max = 150.f ; broadband_shortwave_albedo:long_name = "broadband SW albedo" ; broadband_shortwave_albedo:units = "%" ; float broadband_longwave_flux(time) ; broadband_longwave_flux:valid_min = 0.f ; broadband_longwave_flux:valid_max = 400.f ; broadband_longwave_flux:long_name = "broadband LW flux" ; broadband_longwave_flux:units = "W/m^2" ; float ir_cloud_emittance(time) ; ir_cloud_emittance:valid_min = 0.f ; ir_cloud_emittance:valid_max = 1.5f ; ir_cloud_emittance:long_name = "IR cloud emittance" ; ir_cloud_emittance:units = "unitless" ; int cloud_phase(time) ; cloud_phase:valid_min = 0 ; cloud_phase:valid_max = 7 ; 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" ; float visible_optical_depth(time) ; visible_optical_depth:valid_min = 0.f ; visible_optical_depth:valid_max = 150.f ; visible_optical_depth:long_name = "cloud optical depth" ; visible_optical_depth:units = "unitless" ; float particle_size(time) ; particle_size:valid_min = 0.f ; particle_size:valid_max = 150.f ; particle_size:long_name = "effective particle radius or diameter" ; particle_size:units = "microns" ; particle_size:value_1 = "If phase=1 (water), this parameter is radius." ; particle_size:value_2 = "If phase=2 (ice), this parameter is diameter." ; float liquid_water_path(time) ; liquid_water_path:valid_min = 0.f ; liquid_water_path:valid_max = 6000.f ; 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 (water), this is Liquid Water Path." ; liquid_water_path:value_2 = "NOTE: If phase is 2 (ice), this is Ice Water Path." ; float cloud_effective_temperature(time) ; cloud_effective_temperature:valid_min = 160.f ; cloud_effective_temperature:valid_max = 340.f ; cloud_effective_temperature:long_name = "Effective cloud temperature" ; cloud_effective_temperature:units = "K" ; float cloud_top_pressure(time) ; cloud_top_pressure:valid_min = 0.f ; cloud_top_pressure:valid_max = 1100.f ; cloud_top_pressure:long_name = "cloud top pressure" ; cloud_top_pressure:units = "hPa" ; float cloud_effective_pressure(time) ; cloud_effective_pressure:valid_min = 0.f ; cloud_effective_pressure:valid_max = 1100.f ; cloud_effective_pressure:long_name = "Effective cloud pressure" ; cloud_effective_pressure:units = "hPa" ; float cloud_bottom_pressure(time) ; cloud_bottom_pressure:valid_min = 0.f ; cloud_bottom_pressure:valid_max = 1100.f ; cloud_bottom_pressure:long_name = "cloud bottom pressure" ; cloud_bottom_pressure:units = "hPa" ; float cloud_top_height(time) ; cloud_top_height:valid_min = -0.1f ; cloud_top_height:valid_max = 20.f ; cloud_top_height:long_name = "cloud top height" ; cloud_top_height:units = "km" ; float cloud_effective_height(time) ; cloud_effective_height:valid_min = -0.1f ; cloud_effective_height:valid_max = 20.f ; cloud_effective_height:long_name = "cloud effective height" ; cloud_effective_height:units = "km" ; float cloud_bottom_height(time) ; cloud_bottom_height:valid_min = -0.1f ; cloud_bottom_height:valid_max = 20.f ; cloud_bottom_height:long_name = "cloud bottom height" ; cloud_bottom_height:units = "km" ; // global attributes: :NetCDF_Version = "netCDF 4.0.1" ; :Title = "Pixel-level cloud products " ; :source = "NASA Langley Research Center" ; :version = "V4.0" ; :date = "VISST processed on Jan4 16:09" ; :facility_id = "X1" ; :site_id = "sgp" ; :data_level = "c1" ; :missing_value = "-9999." ; :zeb_platform = "sgpvisstpx04g15v4minnisX1.c1" ; :history = "created by user mk on machine ssai12 at Sat Jan 5 22:43:31 2013 UTC, using IDL 8.1" ; :input_files = "GOES-15" ; :reflectance_vis_note1 = "effective_wavelength_visst = 0.65 um" ; :reflectance_vis_note2 = "spectral_width_instrument = 0.5330 um - 0.7090 um" ; :temperature_sir_note1 = "effective_wavelength_visst = 3.9 um" ; :temperature_sir_note2 = "spectral_width_instrument = 3.7222 um - 4.0958 um" ; :temperature_ir_note1 = "effective_wavelength_visst = 10.8 um" ; :temperature_ir_note2 = "spectral_width_instrument = 10.2145 um - 11.1907 um" ; :temperature_sw_note1 = "effective_wavelength_visst = 13.3 um" ; :temperature_sw_note2 = "spectral_width_instrument = 12.9634 - 13.6203 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 seasonal and separated by day/night. For winter night,a=65.93,b=6.97,c=-0.03250,d=-0.38181. For winter day,a=92.38,b=5.15,c=-0.01639,d=-0.28112. A third order fit was also applied to eliminate low end bias. The fits were derived from 2008-10 GOES-13 vs CERES-Terra Ed3 fluxes over the ARM_SGP domain, and have corresponding winter OLR RMS of night,5.53Wm-2 (2.5%); day, 7.19Wm-2 (2.99%). The CERES limb-darkening function is used to convert NB radiance to flux. REFERENCE: Doelling, D. R, M.M. Khaiyer, and P. Minnis: 2003, Improved ARM-SGP TOA OLR Fluxes from GOES-8 IR Radiances based on CERES data, Proc. of 13th Annual ARM Science Team Meeting, Boulder, CO, March 31 to April 4, 2003. http://www.arm.gov/publications/proceedings/conf13/ " ; :shortwave_NB_BB_correlation = "The SW NB-BB correlation is given by Abb = a + b*Anb + c*Anb*Anb + d*ln(1/cos(SZA)), where Abb is the BB albedo (fraction), Anb is the NB albedo (fraction) and SZA is the solar zenith angle (deg). The coefficients are seasonal; winter:a=0.046838,b=0.697849,c=0.031232,d=0.046153. The relationship was derived from 2008-2010 GOES-13 vs CERES-Terra Ed3 fluxes over the ARM_SGP domain and have corresponding albedo RMS of winter 0.0241 (7.94%). The CERES bidirectional model is used to convert NB reflectance to albedo. REFERENCE: V.Chakrapani, D.R.Doelling, M.M.Khaiyer, and P.Minnis: 2003, New Visible to Broadband Shortwave Conversions for Deriving Albedos from GOES-8 Over the ARM SGP, Proc. of 13th Annual ARM Science Team Meeting, Boulder, CO, March 31 to April 4, 2003. http://www.arm.gov/publications/proceedings/conf13/" ; :visible_calibration = "The GOES-15 visible calibration equation is Rad(0.65um) = (g0 + g1*d + g2*d*d)*(C-C0), where g0=0.7063, g1=0.0, g2=0.0, C= visible channel count, C0=is the visible0 channel offset (29.0), d is the number of days since reference. REFERENCE: Nguyen, L, D.R. Doelling, P. Minnis, J.K. Ayers, 2004, Rapid Technique to cross calibrate satellite imager with visible channels, Proc. of 49th SPIE Meeting, Denver, CO, Aug. 2-6, 2004. http://www-pm.larc.nasa.gov/arm_refs.html" ; :IR_calibration = "The GOES-15 IR calibration was based on the nominal equations used in Mcidas and found at http://www.oso.noaa.gov/goes/goes-calibration/gvar-conversion.htm" ; :VISST = "NASA-Langley cloud and radiation products are produced using the VISST (Visible Infrared Solar-infrared Split-Window Technique), SIST (Solar-infrared Infrared Split-Window Technique) and SINT (Solar-infrared Infrared Near-Infrared Technique). The techniques use GOES-15 channels to detect clouds and retrieve cloud microphysics. Atmospheric profiles are obtained from RUC. REFERENCES: Minnis, P., S. Sun-Mack, D. F. Young, P. W. Heck, D. P. Garber, Y. Chen, D. A. Spangenberg, R. F. Arduini, Q. Z. Trepte, W. L. Smith, Jr., J. K. Ayers, S. C. Gibson, W. F. Miller, V. Chakrapani, Y. Takano, K.-N. Liou, Y. Xie, and P. Yang, 2011: CERES Edition-2 cloud property retrievals using TRMM VIRS and Terra and Aqua MODIS data, Part I: Algorithms. IEEE Trans. Geosci. Remote Sens., 49, 11, 4374-4400.; Minnis, P., L. Nguyen, R. Palikonda, P. W. Heck, D. A. Spangenberg, D. R. Doelling, J. K. Ayers, W. L. Smith, Jr., M. M. Khaiyer, Q. Z. Trepte, L. A. Avey, F.-L. Chang, C. R. Yost, T. L. Chee, and S. Sun-Mack, 2008: Near-real time cloud retrievals from operational and research meteorological satellites. Proc. SPIE Europe Remote Sens. 2008, Cardiff, Wales, UK, 15-18 September, 7107-2, 8 pp. http://www-pm.larc.nasa.gov (Publications link)" ; :DATA_VERSION_NOTE = "This version was re-processed historically and is an intermediate version. As updates are made, the data will be reprocessed in the future and replaced." ; }