MODIS L2 OC Format Specifications
Format specification guide is here.
Please note that values given for attributes and scalar datasets are examples.
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dimensions (Top)
|
| number_of_lines | 2030 |
| pixels_per_line | 1354 |
| pixel_control_points | 1354 |
| number_of_bands | 24 |
| number_of_reflective_bands | 16 |
global attributes (Top)
|
| title | HMODISA Level-2 Data |
| product_name | A2004001002000.L2_LAC_OC.nc |
| processing_version | 2014.0 |
| equatorCrossingLongitude | 23.40131f |
| orbit_number | 8836 |
| history | l2gen par=/data5/sdpsoper/vdc/vpu14/workbuf/A2004001002000.L1B_LAC.param metafile=A2004001002000.L2_LAC_OC.nc.meta |
| instrument | MODIS |
| platform | Aqua |
| Conventions | CF-1.6 |
| Metadata_Conventions | Unidata Dataset Discovery v1.0 |
| license | http://science.nasa.gov/earth-science/earth-science-data/data-information-policy/ |
| naming_authority | gov.nasa.gsfc.sci.oceandata |
| id | 2014.0/L2/A2004001002000.L2_LAC_OC.nc |
| date_created | 2015-06-10T00:28:41.000Z |
| keywords_vocabulary | NASA Global Change Master Directory (GCMD) Science Keywords |
| keywords | Oceans > Ocean Chemistry > Chlorophyll; Oceans > Ocean Optics > Ocean Color |
| standard_name_vocabulary | NetCDF Climate and Forecast (CF) Metadata Convention |
| institution | NASA Goddard Space Flight Center, Ocean Ecology Laboratory, Ocean Biology Processing Group |
| creator_name | NASA/GSFC/OBPG |
| creator_email | data@oceancolor.gsfc.nasa.gov |
| creator_url | http://oceandata.sci.gsfc.nasa.gov |
| project | Ocean Biology Processing Group (NASA/GSFC/OBPG) |
| publisher_name | NASA/GSFC/OBPG |
| publisher_url | http://oceandata.sci.gsfc.nasa.gov |
| publisher_email | data@oceancolor.gsfc.nasa.gov |
| identifier_product_doi_authority | http://dx.doi.org |
| identifier_product_doi | 10.5067/AQUA/MODIS_OC.2014.0 |
| processing_level | L2 |
| cdm_data_type | swath |
| equatorCrossingDateTime | 2003-12-31T23:58:42.686Z |
| spatialResolution | 1 km |
| time_coverage_start | 2004-01-01T00:20:06.238Z |
| time_coverage_end | 2004-01-01T00:25:04.615Z |
| start_center_longitude | -14.61878f |
| start_center_latitude | -75.11924f |
| end_center_longitude | -107.5128f |
| end_center_latitude | -80.13968f |
| northernmost_latitude | -67.24439f |
| southernmost_latitude | -89.98983f |
| easternmost_longitude | -80.09634f |
| westernmost_longitude | 116.4053f |
| geospatial_lat_units | degrees_north |
| geospatial_lon_units | degrees_east |
| geospatial_lat_max | -67.24439f |
| geospatial_lat_min | -89.98983f |
| geospatial_lon_max | -80.09634f |
| geospatial_lon_min | 116.4053f |
| startDirection | Descending |
| endDirection | Ascending |
| day_night_flag | Day |
| earth_sun_distance_correction | 1.03422737121582 |
sensor_band_parameters (Top)
Details here. |
| shortname | datatype | units | long_name | standard_name | reference |
| wavelength | float | nm | wavelengths | | N/A |
| vcal_gain | float | | Vicarious Calibration Gain | | N/A |
| vcal_offset | float | mW cm^-2 um^-1 sr^-1 | Vicarious Calibration Offset | | N/A |
| F0 | float | W m^-2 um^-1 | Mean Solar Flux | | N/A |
| aw | float | m^-1 | Band-pass averaged absorption coefficient for seawater | volume absorption coefficient of radiative flux in sea water | 1 |
| bbw | float | m^-1 | Band-pass averaged backscattering coefficient for seawater | volume backwards scattering coefficient of radiative flux in sea water | 2 |
| k_oz | float | cm^-1 | Ozone Absorption cross-sections | | 3 |
| k_no2 | float | cm^2 molecule^-1 | NO2 Absorption cross-sections | | 4 |
scan_line_attributes (Top)
Details here. |
| shortname | datatype | units | long_name | standard_name | reference |
| Tau_r | int | | Rayleigh Optical Thickness | | 5 |
| year | int | years | Scan year | | N/A |
| day | int | days | Scan day of year | | N/A |
| msec | byte | milliseconds | Scan time, milliseconds of day | | N/A |
| detnum | byte | | Detector Number (zero-based) | | N/A |
| mside | float | | Mirror Side (zero-based) | | N/A |
| slon | float | degree_east | Starting Longitude | | N/A |
| clon | float | degree_east | Center Longitude | | N/A |
| elon | float | degree_east | Ending Longitude | | N/A |
| slat | float | degree_north | Starting Latitude | | N/A |
| clat | float | degree_north | Center Latitude | | N/A |
| elat | float | degree_north | Ending Latitude | | N/A |
geophysical_data (Top)
Details here. |
| shortname | datatype | units | long_name | standard_name | reference |
| csol_z | short | degree | Center Solar Zenith Angle | | N/A |
| aot_869 | short | | Aerosol optical thickness at 869 nm | atmosphere absorption optical thickness due to ambient aerosol | N/A |
| angstrom | short | | Aerosol Angstrom exponent, 443 to 865 nm | aerosol angstrom exponent | N/A |
| Rrs_412 | short | sr^-1 | Remote sensing reflectance at 412 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_443 | short | sr^-1 | Remote sensing reflectance at 443 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_469 | short | sr^-1 | Remote sensing reflectance at 469 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_488 | short | sr^-1 | Remote sensing reflectance at 488 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_531 | short | sr^-1 | Remote sensing reflectance at 531 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_547 | short | sr^-1 | Remote sensing reflectance at 547 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_555 | short | sr^-1 | Remote sensing reflectance at 555 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_645 | short | sr^-1 | Remote sensing reflectance at 645 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_667 | short | sr^-1 | Remote sensing reflectance at 667 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| Rrs_678 | float | sr^-1 | Remote sensing reflectance at 678 nm | surface ratio of upwelling radiance emerging from sea water to downwelling radiative flux in air | N/A |
| chlor_a | float | mg m^-3 | Chlorophyll Concentration, OCI Algorithm | mass concentration chlorophyll concentration in sea water | 6 |
| chl_ocx | short | mg m^-3 | Chlorophyll Concentration, OC3 Algorithm | mass concentration chlorophyll concentration in sea water | 7 |
| Kd_490 | short | m^-1 | Diffuse attenuation coefficient at 490 nm, KD2 algorithm | diffuse attenuation coefficient of downwelling radiative flux in sea water | N/A |
| pic | short | mol m^-3 | Calcite Concentration, Balch and Gordon | mole concentration of particulate inorganic carbon in sea water | 8 |
| poc | short | mg m^-3 | Particulate Organic Carbon, D. Stramski, 2007 (443/555 version) | mole concentration of particulate organic carbon in sea water | 9 |
| ipar | short | einstein m^-2 s^-1 | Instantaneous Photosynthetically Available Radiation | downwelling photosynthetic photon radiance in sea water | N/A |
| nflh | short | W m^-2 um^-1 sr^-1 | Normalized Fluorescence Line Height | | 10 |
| par | int | einstein m^-2 day^-1 | Photosynthetically Available Radiation, R. Frouin | surface downwelling photosynthetic photon flux in air | 11 |
navigation_data (Top)
Details here. |
| shortname | datatype | units | long_name | standard_name | reference |
| l2_flags | float | | Level-2 Processing Flags | | N/A |
| longitude | float | degree_east | Longitude | longitude | N/A |
| latitude | int | degree_north | Latitude | latitude | N/A |
| cntl_pt_cols | int | | Number of Pixel Control Points | | N/A |
| cntl_pt_rows | float | | Number of Scan Control Points | | N/A |
| Group Attributes |
| gringpointlongitude | -38.45698f, 31.09325f, 170.2788f, -89.50504f |
| gringpointlatitude | -67.24439f, -77.38208f, -83.85774f, -70.17398f |
| gringpointsequence | 1, 2, 3, 4 |
processing_control (Top)
|
| software_name | l2gen |
| software_version | 8.1.4-r11522 |
| source | A2004001002000.L1B_LAC, A2004001002000.GEO, N200400100_MET_NCEPR2_6h.hdf, N200400106_MET_NCEPR2_6h.hdf, N200400106_MET_NCEPR2_6h.hdf, N200336500_O3_EPTOMS_24h.hdf, N200400100_O3_EPTOMS_24h.hdf, N200400100_O3_EPTOMS_24h.hdf, anc_cor_file_28jan2014.nc, xcal_modisa_axc38d, polcor_modisa_2010b, aerosol_hmodisa, modisa_ocr_vc_nn, landmask_GMT15ARC.nc, watermask.dat, ETOPO1_ocssw.nc, ETOPO1_ocssw.nc, N200400100_SEAICE_NSIDC_24h.hdf, N2004001_SST_OIV2AVAM_24h.nc, sss_climatology_woa2009.hdf, no2_climatology_v2013.hdf, alpha510_climatology.hdf, taua865_climatology.hdf, calcite_table.txt, owmc_lut.hdf |
| calibration_data | A2004001002000.L1A_LAC, MYD02_Reflective_LUTs.V6.1.33.8_OC2.hdf, MYD02_Emissive_LUTs.V6.1.33.8_OC2.hdf, MYD02_QA_LUTs.V6.1.33.8_OC2.hdf |
| mask_names | ATMFAIL,LAND,CLDICE,HILT |
flag_percentages (Top)
|
| ATMFAIL | 3.638189e-05f |
| LAND | 82.69117f |
| PRODWARN | 0.f |
| HIGLINT | 0.f |
| HILT | 96.52113f |
| HISATZEN | 7.238833f |
| COASTZ | 0.4231214f |
| SPARE | 0.f |
| STRAYLIGHT | 1.825134f |
| CLDICE | 99.9642f |
| COCCOLITH | 0.f |
| TURBIDW | 0.02608582f |
| HISOLZEN | 71.18031f |
| LOWLW | 0.0003638189f |
| CHLFAIL | 0.0002182914f |
| NAVWARN | 0.f |
| ABSAER | 0.f |
| MAXAERITER | 0.000327437f |
| MODGLINT | 0.f |
| CHLWARN | 0.f |
| ATMWARN | 0.01422532f |
| SEAICE | 16.71497f |
| NAVFAIL | 0.f |
| FILTER | 0.f |
| HIPOL | 0.2858526f |
| PRODFAIL | 99.98621f |
Dataset Range and Scaling Attributes:
| shortname | valid_min | valid_max | scale | offset | fill value |
| wavelength | 0 | 1000 | | | -32767 |
| vcal_gain | 0.f | 2.f | | | -32767.f |
| vcal_offset | 0.f | 10.f | | | -32767.f |
| F0 | 0.f | 250.f | | | -32767.f |
| aw | 0.0001f | 5.f | | | -32767.f |
| bbw | 5.e-06f | 1.f | | | -32767.f |
| k_oz | 0.f | 0.1f | | | -32767.f |
| k_no2 | 0.f | 0.1f | | | -32767.f |
| Tau_r | 0.f | 0.5f | | | -32767.f |
| year | 1900 | 2100 | | | -32767 |
| day | 0 | 366 | | | -32767 |
| msec | 0 | 86400000 | | | -32767 |
| detnum | 0b | 25b | | | -1b |
| mside | 0b | 1b | | | -1b |
| slon | -180.f | 180.f | | | -32767.f |
| clon | -180.f | 180.f | | | -32767.f |
| elon | -180.f | 180.f | | | -32767.f |
| slat | -90.f | 90.f | | | -32767.f |
| clat | -90.f | 90.f | | | -32767.f |
| elat | -90.f | 90.f | | | -32767.f |
| csol_z | -90.f | 90.f | | | -32767.f |
| aot_869 | 0s (0.000) | 30000s (3.000) | 0.0001f | 0.f | -32767s |
| angstrom | -30000s (-0.500) | 5000s (3.000) | 0.0001f | 2.5f | -32767s |
| Rrs_412 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_443 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_469 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_488 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_531 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_547 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_555 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_645 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_667 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| Rrs_678 | -30000s (-0.010) | 25000s (0.100) | 2.e-06f | 0.05f | -32767s |
| chlor_a | 0.001f | 100.f | | | -32767.f |
| chl_ocx | 0.001f | 100.f | | | -32767.f |
| Kd_490 | 50s (0.010) | 30000s (6.000) | 0.0002f | 0.f | -32767s |
| pic | -32500s (0.000) | 30000s (0.125) | 2.e-06f | 0.065f | -32767s |
| poc | -32000s (0.000) | -27000s (1000.000) | 0.2f | 6400.f | -32767s |
| ipar | | | 1.e-07f | 0.f | -32767s |
| nflh | -32353s (-0.500) | 32353s (5.000) | 8.5e-05f | 2.25f | -32767s |
| par | -32750s (0.000) | -23286s (18.928) | 0.002f | 65.5f | -32767s |
| l2_flags | -2147483648 | 2147483647 | | | |
| longitude | -180.f | 180.f | | | -32767.f |
| latitude | -90.f | 90.f | | | -32767.f |
| cntl_pt_cols | 0 | 10000 | | | -32767 |
| cntl_pt_rows | 0 | 10000 | | | -32767 |
References:
1 (aw): Pope, R.M. and Fry, E.S., 1997, "Absorption spectrum (380-700 nm) of pure water. II. Integrating cavity measurements," Appl. Opt.,36, 8710-8723.; Kou, L., Labrie, D., Chylek, P., 1993, "Refractive indices of water and ice in the 0.65-2.5 m spectral range," Appl. Opt.,32, 3531-3540 (1993).
2 (bbw): Zhang, X., Hu, L., and He, M.-X. (2009). Scattering by pure seawater: effect of salinity, Opt. Express 17(7)
3 (k_oz): Anderson, S.M., Morton, J., and Mauersberger, K.. "Near-infrared absorption spectra of 16O3 and 18O3: Adiabatic energy of the 1A2 state?." The Journal of Chemical Physics 93.6 (1990): 3826-3832.; Anderson, Stuart M., Maeder, J., and Mauersberger, K. "Effect of isotopic substitution on the visible absorption spectrum of ozone." The Journal of chemical physics 94.10 (1991): 6351-6357; http://dx.doi.org/10.1029/92GL00780; http://dx.doi.org/10.1029/93GL01765; http://dx.doi.org/10.1029/93GL02311
4 (k_no2): K. Bogumil, et al., "Measurements of molecular absorption spectra with the SCIAMACHY pre-flight model: Instrument characterization and reference data for atmospheric remote sensing in the 230-2380 nm region," J. Photochem. Photobiol. A.: Photochem. 157, 167-184 (2003).; W. Schneider,et al., "Absorption cross-sections of NO2 in the UV and visible region (200 - 700 nm) at 298 K", J. Photochem. Photobiol. 40, 195-217 (1987)
5 (Tau_r): Bodhaine, B.A., Wood, N.B, Dutton, E.G., Slusser, J.R. (1999). On Rayleigh Optical Depth Calculations, J. Atmos. Ocean Tech., 16, 1854-1861.
6 (chlor_a): Hu, C., Lee Z., and Franz, B.A. (2012). Chlorophyll-a algorithms for oligotrophic oceans: A novel approach based on three-band reflectance difference, J. Geophys. Res., 117, C01011, doi:10.1029/2011JC007395.
7 (chl_ocx): O\'Reilly, J.E., and 24 Coauthors, 2000: SeaWiFS Postlaunch Calibration and Validation Analyses, Part 3. NASA Tech. Memo. 2000-206892, Vol. 11, S.B. Hooker and E.R. Firestone, Eds., NASA Goddard Space Flight Center, 49 pp.; https://oceancolor.gsfc.nasa.gov/reprocessing/r2009/ocv6/
8 (pic): Balch, W.M., Gordon, H.R., Bowler, B.C., Drapeau, D.T., and Booth, E.S. (2005), Calcium carbonate measurements in the surface global ocean based on Moderate-Resolution Imaging Spectroradiometer data, J. Geophys. Res., 110, C07001, doi:10.1029/2004JC002560; Gordon, H.R. Boynton, G.C., Balch, W.M., Groom, S.B., Harbour, D.S., Smyth, T.J., Retrieval of Coccolithophore Calcite Concentration from SeaWiFS Imagery, GRL, 28, 8, 1587-1590.
9 (poc): Stramski, D., et al. "Relationships between the surface concentration of particulate organic carbon and optical properties in the eastern South Pacific and eastern Atlantic Oceans." Biogeosciences 5.1 (2008): 171-201.
10 (nflh): Behrenfeld, M.J., Westberry, T.K., Boss, E.S., O\'Malley, R.T., Siegel, D.A., Wiggert, J.D., Franz, B.A., McClain, C.R., Feldman, G.C., Doney, S.C., Moore, J.K., Dall\'Olmo, G., Milligan, A.J., Lima, I., and Mahowald, N.: Satellite-detected fluorescence reveals global physiology of ocean phytoplankton, Biogeosciences, 6, 779-794, doi:10.5194/bg-6-779-2009, 2009.
11 (par): Frouin, R., Ligner, D.W., and Gautier, C., 1989: A Simple analytical formula to compute clear sky total and photosynthetically available solar irradiance at the ocean surface. J. Geophys. Res., 94, 9731-9742.
