Product | Description/Use | Availability/Latency | Status |
---|---|---|---|
Calibrated Radiometry and Polarimetry | |||
Spectral top-of-atmosphere radiances from OCI | Spectral radiance observed at the top of the atmosphere. | Level-1B: daily Level-1C: daily | Standard Product |
Spectral top-of-atmosphere radiances and polarimetry from SPEXone | Spectral radiance and polarimetry observed at the top of the atmosphere, for all sensor viewing angles. | Level-1B: daily Level-1C: daily | Standard Product |
Spectral top-of-atmosphere radiances and polarimetry from HARP2 | Spectral radiance and polarimetry observed at the top of the atmosphere, for all sensor viewing angles. | Level-1B: daily Level-1C: daily | Standard Product |
Ocean Properties to be Produced by OCI | |||
Spectral remote sensing reflectances | Spectral color of the ocean in the ultraviolet-to-near infrared spectral range. Used as input into algorithms to retrieve information about colored dissolved organic matter, phytoplankton, non-algal particles, and other aquatic constituents. Provided in continuous 2.5-nm steps from 350 to 717.5-nm with a resolution (bandwidth) of 5-nm. | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Apparent visible wavelength | An optical water classification index reported as the weighted harmonic mean of visible-range Rrs wavelengths (400-700 nm). | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Spectral diffuse attenuation coefficients | Spectral diffuse attenuation of downwelling irradiance at multiple wavelengths between 350 and 700 nm. Provides indices of water clarity and light penetration. | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Spectral phytoplankton absorption coefficients | Spectral absorption coefficients for total phytoplankton absorption at multiple wavelengths between 350 and 700-nm. Provides information on phytoplankton physiology, abundance, and community composition. | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Spectral non-algal particle plus dissolved organic matter absorption coefficients | Spectral absorption coefficients for non-algal particulates and dissolved organic matter at multiple wavelengths between 350 and 700-nm. Provides information on the concentrations of the dissolved component of organic carbon and the detrital (non-algal) component of the particulate assembly. | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Spectral chromophoric dissolved organic matter absorption coefficients | Spectral absorption coefficients for dissolved organic matter at multiple wavelengths between 350 and 700-nm. Provides information on the concentration of the dissolved component of organic carbon. | TBD | Test |
Spectral slope coefficients of chromophoric dissolved organic matter absorption | Absorption spectral slope coefficients of chromophoric dissolved organic matter for multiple wavelength ranges: 275-295, 350-400, 380-600 nm. Provides information on the contribution of land-derived dissolved organic matter, relative contribution of land- versus marine-derived dissolved organic matter, and as a relative measure of solar photobleaching. | TBD | Test |
Spectral non-algal particle matter absorption coefficients | Spectral absorption coefficients for non-algal particulate matter at multiple wavelengths between 350 and 700 nm. Provides information on the concentration of non-phytoplankton particulate components. | TBD | Test |
Spectral particlulate matter absorption coefficients | Spectral absorption coefficients for particulate matter at multiple wavelengths between 350 and 700 nm. Provides information on the concentration of particulate matter in the water column. | TBD | Test |
Spectral particle backscattering coefficients | Spectral backscattering of the light associated with particulate material, at multiple wavelengths between 350-700 nm. Provides an indicator of the concentration of particules in the ocean and a proxy indicator of particulate carbon concentrations. | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Fluorescence line height | Light leaving the surface ocean due to the sun induced chlorophyll fluorescence. Provides an indicator of phytoplankton physiology (health?). | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Daily photosynthetically available radiation (PAR) | The amount of sunlight that is useful for photosynthesis, defined here as the 400-700 nm spectral range, that reaches the surface of the ocean over a day. As phytoplankton require light to convert inorganic carbon to organic carbon, PAR provides a critical parameter for understanding the oceanic carbon cycle. | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Instantaneous photosynthetically available radiation (iPAR) | The amount of sunlight that is useful for photosynthesis, defined here as the 400-700 nm spectral range, that reaches the surface of the ocean at the moment of satellite data collection. As phytoplankton require light to convert inorganic carbon to organic carbon, iPAR provides a critical parameter for understanding the oceanic carbon cycle. | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Concentration of chlorophyll-a | Near surface concentration of the photosynthetic pigment chlorophyll-a. Provides proxies for algal biomass, ecosystem health and function, and eutrophication. | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Phytoplankton pigment concentrations | Concentration of specific photosynthetic pigments in the surface ocean. As different phytoplankton taxa contain their own specific pigment suites, these concentrations provide indicators of presence and abundance of specific types of phytoplankton in the ocean (e.g. harmful algal blooms). | TBD | Test |
Net primary production (NPP) | Rate of conversion of dissolved carbon dioxide to organic carbon through photosysthesis minus the carbon used for respiration. NPP is an important part of the carbon cycle and these products are used in local models (estimating food avaliable to fish populations) all the way up to global climate and Earth System models (to predict information about the oceans of today and tomorrow). | TBD | Test |
Phytoplankton community composition | Descriptors of the composition of phytoplankton populations. Different approaches describe these populations in different ways, such as by carbon content or biovolume per class (e.g., diatom contributions vs. cyanobacteria contributions), particle size distributions (or fraction of large cells vs. small cells), or targeted identification of a single class (e.g., detection of a harmful cyanobacteria algal bloom). | TBD | Test |
Concentration of particulate organic carbon | Near surface concentration of the particulate organic carbon. It is a proxy for all living material (phytoplankton, zooplankton, bacteria) and detritus. It is also a venue through which organic carbon, sequestered through the photosynthesis, is transferred towards higher trophic levels and into the deep ocean. | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Concentration of particulate inorganic carbon | Concentration of particulate inorganic carbon in the surface of the ocean. Used to track the presence and abundance of calcite containing phytoplankton in the open ocean (coccolithophores). | Level-2: daily Level-3: daily, 8-day, monthly, annual | Standard Product |
Concentration of phytoplankton carbon | Concentration of carbon contained in phytoplankton cells. Provides a proxy for phytoplankton biomass that is often used in primary productivity algorithms and biogeochemical and Earth System models. | Level-2: daily Level-3: daily, 8-day, monthly, annual | Provisional |
Concentration of dissolved organic carbon | Near surface concentration of dissolved organic carbon. It is exported into coastal waters from land through rivers and groundwater. In the aquatic environment, it is produced or released by all living material (phytoplankton, zooplankton, bacteria) and detritus. It is a source of energy for bacteria and other microbial organisms and is transferred to higher trophic levels. It typically comprises well over 95% of the organic carbon in the ocean. | TBD | Test |
Suspended particulate matter | Near surface concentration of particles both living (phytoplankton, zooplankton, bacteria) and non-living (detritus, sediments). | TBD | Test |
Atmospheric Properties to be Produced by OCI | |||
Spectral aerosol optical depth | Spectral measurement of the extinction of the solar beam caused by atmospheric aerosol particles, such as dust and haze, at 380, 440, 500, 550, and 675 nm (and potentially additional wavelengths) over land and oceans. Provides information on the concentration of aerosols in a vertical column of atmosphere. | Level-2: daily Level-3: daily, 8-day, monthly | Standard Product |
Aerosol fine mode fraction (over ocean) | Fraction of visible aerosol optical depth from fine mode aerosols over oceans at 550 nm. | Level-2: daily Level-3: daily, 8-day, monthly | Standard Product |
Cloud mask | Provides information on whether or not a given pixel is covered by cloud. This is an input to many downstream algorithms, as most process either only cloudy or only cloud-free scenes, and is also useful for climate research. | Level-2: daily Level-3: daily, 8-day, monthly | Standard Product |
Cloud phase | Provides information on whether a given cloudy pixel is composed of liquid-phase or ice-phase clouds. Used as an input to downstream processing to inform optical model choices, as well as for climate research. | Level-2: daily Level-3: daily, 8-day, monthly | Standard Product |
Cloud top pressure of opaque clouds | Atmospheric pressure at the height of the cloud top. Useful for climate research and in L1c reaggregation. | Level-2: daily Level-3: daily, 8-day, monthly | Standard Product |
Optical thickness of liquid and ice clouds | Measurement of extinction of the solar beam due to clouds in the mid-visible wavelength. Used for climate studies. | Level-2: daily Level-3: daily, 8-day, monthly | Standard Product |
Effective radius of liquid and ice clouds | Ratio of the third to second moments of the cloud droplet size distribution, as an indicator of cloud particle size. Used for climate studies. | Level-2: daily Level-3: daily, 8-day, month | Standard Product |
Water path of liquid and ice clouds | Mass of (liquid or ice) water in clouds in the vertical column. Used for climate studies. | Level-2: daily Level-3: daily, 8-day, monthly | Standard Product |
Shortwave radiation effect | Reflected solar flux (spectral and directional integral of reflected sunlight). | Level-2: daily Level-3: daily, monthly | Standard Product |
Land Data Products to be Produced by OCI | |||
Surface reflectance | Effective reflectance of the Earth's surface as observed by OCI. Used as an input to downstream land data products. | TBD | Test |
BRDF/albedo and model parameters | Describes the spectral and directional dependence of surface reflectance. | TBD | Test |
Normalized difference vegetation index (NDVI) | Empirical metric related to vegetation abundance and health, corrected for atmospheric scattering and absorption. | TBD | Test |
Enhanced vegetation index (EVI) | Empirical metric related to vegetation abundance and health, similar to NDVI, with additional resistance to atmospheric effects and sensitivity in densely vegetated regions. | TBD | Test |
Photochemical reflectance index (PRI) | Hyperspectral vegetation index designed to capture subtle shifts in carotenoids and provides information on stress in plants | TBD | Test |
Aerosol and Ocean Properties from HARP2 | |||
Spectral aerosol optical depth | Spectral measurement of the extinction of the solar beam caused by atmospheric aerosol particles. Provides information on the concentration of aerosols in a vertical column of atmosphere. May be represented separately for different aerosol size/type modes. | TBD | Test |
Aerosol size distribution | Multiple parameters describing the distribution of aerosol sizes. May include multiple size modes or bins. | TBD | Test |
Aerosol complex refractive index | Real and imaginary component of refractive index for each aerosol mode. This defines aerosol extinction, scattering and absorption. | TBD | Test |
Aerosol layer height | Parameterization of aerosol vertical distribution. | TBD | Test |
Aerosol shape, fraction spherical | Fraction of aerosols that are treated as spheres versus other shapes, such as spheroids. | TBD | Test |
Spectral remote sensing reflectances | Spectral color of the ocean in the visible spectral range. Used to evaluate performance of atmospheric correction based on aerosol properties retrieved from polarimeters, faciliate synergy with other instruments. | TBD | Test |
Aerosol single scattering albedo | Ratio of aerosol scattering to extinction. | TBD | Test |
Ocean surface roughness | Surface roughness defines the directionality of the solar specular reflectance (sunglint), often parameterized by wind speed and direction. | TBD | Test |
Ocean body properties | In water optical properties that define the water leaving radiance. Parameterization schemes may be simple or complex, the validity of which depend on ocean conditions. | TBD | Test |
Aerosol and Land Surface Properties from HARP2 | |||
Spectral aerosol optical depth | Spectral measurement of the extinction of the solar beam caused by atmospheric aerosol particles. Provides information on the concentration of aerosols in a vertical column of atmosphere. May be represented separately for different aerosol size/type modes. | TBD | Test |
Aerosol number concentration | Number of aerosols present within a defined volume or area. | TBD | Test |
Aerosol size distribution | Multiple parameters describing the distribution of aerosol sizes. May include multiple size modes or bins. | TBD | Test |
Aerosol complex refractive index | Real and imaginary component of refractive index for each aerosol mode. This defines aerosol extinction, scattering and absorption. | TBD | Test |
Aerosol layer height | Parameterization of aerosol vertical distribution. | TBD | Test |
Aerosol shape, fraction spherical | Fraction of aerosols that are treated as spheres versus other shapes, such as spheroids. | TBD | Test |
Aerosol single scattering albedo | Ratio of aerosol scattering to extinction. | TBD | Test |
Spectrally resolved land surface Bidirectional Reflectance Distribution Function (BRDF) | Defines the reflectance as a function of illumination and observation characteristics. Often represented as a modal sum of angular distribution kernels. | TBD | Test |
Spectrally resolved land surface Bidirectional Polarized Distribution Function (BPDF) | Defines the surface polarization as a function of illumination and observation characteristics. | TBD | Test |
Cloud Properties from HARP2 | |||
Cloud detection | Cloud identification, either as binary flag, percentage or other metric. | TBD | Test |
Cloud physical thickness | Distance between cloud base and cloud top. | TBD | Test |
Cloud top height | Altitude of cloud top. | TBD | Test |
Cloud top phase | Determination of liquid or ice phase cloud. | TBD | Test |
Cloud optical depth | Synonymous with cloud optical thickness. | TBD | Test |
Liquid cloud droplet effective radius and effective variance | A microphysical property describing droplet size distribution and distribution width. | TBD | Test |
Ice particle shape and asymmetry parameter | Parameterization of shape is relevant for radiative transfer modeling. | TBD | Test |
Liquid water path | Can be derived from measures of optical depth and droplet size distribution. | TBD | Test |
3D cloud field | 3D reconstruction of cloud vertical and horizontal distribution using multi-angle polarimetry. | TBD | Test |
Ocean Surface Properties from HARP2 | |||
Aerosol optical depth in the near infrared | Byproduct of the primary algorithm. | TBD | Test |
Ocean surface refractive index | Indication of non-seawater substances on the ocean surface, such as oil. | TBD | Test |
Aerosol and Ocean Properties from SPEXone | |||
Spectral aerosol optical depth | Spectral measurement of the extinction of the solar beam caused by atmospheric aerosol particles. Provides information on the concentration of aerosols in a vertical column of atmosphere. May be represented separately for different aerosol size/type modes. | TBD | Test |
Aerosol size distribution | Multiple parameters describing the distribution of aerosol sizes. May include multiple size modes or bins. | TBD | Test |
Aerosol complex refractive index | Real and imaginary component of refractive index for each aerosol mode. This defines aerosol extinction, scattering and absorption. | TBD | Test |
Aerosol layer height | Parameterization of aerosol vertical distribution. | TBD | Test |
Aerosol shape, fraction spherical | Fraction of aerosols that are treated as spheres versus other shapes, such as spheroids. | TBD | Test |
Aerosol single scattering albedo | Ratio of aerosol scattering to extinction. | TBD | Test |
Ocean surface roughness | Surface roughness defines the directionality of the solar specular reflectance (sunglint), often parameterized by wind speed and direction. | TBD | Test |
Ocean body properties | In water optical properties that define the water leaving radiance. Parameterization schemes may be simple or complex, the validity of which depend on ocean conditions. | TBD | Test |
Aerosol and Land Surface Properties from SPEXone | |||
Spectral aerosol optical depth | Spectral measurement of the extinction of the solar beam caused by atmospheric aerosol particles. Provides information on the concentration of aerosols in a vertical column of atmosphere. May be represented separately for different aerosol size/type modes. | TBD | Test |
Aerosol number concentration | Number of aerosols present within a defined volume or area. | TBD | Test |
Aerosol size distribution | Multiple parameters describing the distribution of aerosol sizes. May include multiple size modes or bins. | TBD | Test |
Aerosol complex refractive index | Real and imaginary component of refractive index for each aerosol mode. This defines aerosol extinction, scattering and absorption. | TBD | Test |
Aerosol layer height | Parameterization of aerosol vertical distribution. | TBD | Test |
Aerosol shape, fraction spherical | Fraction of aerosols that are treated as spheres versus other shapes, such as spheroids. | TBD | Test |
Aerosol single scattering albedo | Ratio of aerosol scattering to extinction. | TBD | Test |
Spectrally resolved land surface Bidirectional Reflectance Distribution Function (BRDF) | Defines the reflectance as a function of illumination and observation characteristics. Often represented as a modal sum of angular distribution kernels. | TBD | Test |
Spectrally resolved land surface Bidirectional Polarized Distribution Function (BPDF) | Defines the surface polarization as a function of illumination and observation characteristics. | TBD | Test |
Aerosol and Ocean Properties from OCI + HARP2 + SPEXone | |||
Spectral aerosol optical depth | Spectral measurement of the extinction of the solar beam caused by atmospheric aerosol particles. Provides information on the concentration of aerosols in a vertical column of atmosphere. May be represented separately for different aerosol size/type modes. | TBD | Test |
Aerosol size distribution | Multiple parameters describing the distribution of aerosol sizes. May include multiple size modes or bins. | TBD | Test |
Aerosol complex refractive index | Real and imaginary component of refractive index for each aerosol mode. This defines aerosol extinction, scattering and absorption. | TBD | Test |
Aerosol layer height | Parameterization of aerosol vertical distribution. | TBD | Test |
Aerosol shape, fraction spherical | Fraction of aerosols that are treated as spheres versus other shapes, such as spheroids. | TBD | Test |
Aerosol scattering phase matrix | Defined by above parameters, this describes the angular distribution of scattering and polarization. | TBD | Test |
Aerosol single scattering albedo | Ratio of aerosol scattering to extinction. | TBD | Test |
Spectral remote sensing reflectances | Spectral color of the ocean in the visible spectral range. Used to evaluate performance of atmospheric correction based on aerosol properties retrieved from polarimeters, faciliate synergy with other instruments | TBD | Test |
Ocean surface roughness | Surface roughness defines the directionality of the solar specular reflectance (sunglint), often parameterized by wind speed and direction. | TBD | Test |
Ocean body properties | In water optical properties that define the water leaving radiance. Parameterization schemes may be simple or complex, the validity of which depend on ocean conditions. | TBD | Test |
Thin cloud contamination | Some algorithms may detect the presence of optically thin clouds (usually cirrus) that would otherwise adversely affect the retrieval of other parameters. | TBD | Test |
NASA's Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) platform measures the distribution of phytoplankton, a key indicator of ocean health.
Type
Data Center
Launch
Objective
PACE carries three instruments:
- Ocean Color Instrument (OCI): Primary instrument; hyperspectral radiometer
- Hyper Angular Research Polarimeter (HARP2): multi-angle polarimeter
- Spectro-polarimeter for Planetary Exploration (SPEXone): multi-angle polarimeter
Parameter | OCI | HARP2 | SPEXone |
---|---|---|---|
Spectral Range/Bandwidth | 342.5 - 887.5 at 5 nm steps | 440, 550, 670 (10 nm), 870 (40 nm) | 385 - 770 nm at 2 - 4 nm steps |
Shortwave Infrared (OCI)/Polarized Bands (HARP2, SPEXone) | Seven bands centered on 940, 1038, 1250, 1378, 1615, 2130, 2260 nm | All | Same range in 15 to 45 nm steps |
Number of Viewing Angles | Fore-aft tilt ± 20° to avoid sunglint | 10 for 440, 550, 870 nm; 60 to 670 nm (spaced over 114° | Five (-57°, -20°, 0°, 20°, 57°) |
Coverage (Swath Width) | ± 56.5° (2663 km at 20° tilt) | ± 47° (1556 km at nadir) | ± 4.5° (106 km at nadir) |
Global Coverage | 1-2 days | 2 days | 30+ days |
Ground Pixel | 1 km at nadir | 3 km | 2.5 km |
Institution(s) | NASA's Goddard Space Flight Center in Greenbelt, Maryland | University of Maryland - Earth and Space Institute | SRON Netherlands Institute for Space Research, Airbus Defense and Space Netherlands, TINO |
The OCI will have a maximum 2500 km swath width, a resolution of 1 km and a 5 nm spectral resolution. It will be capable of wavelength measurements from ultraviolet (340 nm) to near-infrared (890 nm)
SPEXone is a spectro-polarimeter that provides continuous wavelengths coverage in the range 385-770 nm. Spectral resolution is 2-5 nm for radiance and 10-40 nm for DoLP. It observes a ground pixel under 5 viewing angles (0°, ±22° and ±58° on ground), where the ±22° viewports will be used for cross calibration with OCI.
HARP2 will combine data from multiple along track viewing angles (up to 60), four spectral bands in the visible and near infrared ranges, and three angles of linear polarization to measure the microphysical properties of the atmospheric particles including their size distribution, amount, refractive indices, and particle shape.
All science data files produced from PACE will follow the standard naming convention of NASA's Ocean Biology Processing Group (OBPG). The filename leader will be PACE_OCI, PACE_HARP, or PACE_SPEX for OCI, HARP2, and SPEXone, respectively.
OBPG naming convention:
MMMM_IIII_TTT.YYYYMMDDTHHMMSS.LLLL.PPPP.SSSS.pppp.RRRR.NRT.nc
- MMMM*: variable-length uppercase character string indicating the "mission".
- e.g. AQUA, PACE, S3A
- IIII: variable-length uppercase character string indicating the instrument
- e.g. OCI (PACE Ocean Color Instrument)
- TTT: (value is absent if not relevant to product) variable-length uppercase character string indicating the data "type"
- e.g. GAC (SeaWiFS Global Area Coverage); EFR (OLCI Full Resolution)
- YYYYMMDDTHHMMSS: ISO8601 time format, where YYYY is the 4-digit year, MM is the two-digit month, DD is the two-digit day, T indicates the time follows this character, HHMMSS are the two-digit hour, minutes, and seconds, respectively.
- LLLL: variable-length character string indicating the level.
- e.g. L1B, L2, L3m
- PPPP: period indicator for L3
- e.g. DAY, MO, YR, R32
- SSSS: suite identifier
- e.g. RRS, CHL
- pppp: product identifier
- e.g. Rrs_412, chlor_a
- RRRR**: resolution
- e.g. 4km
- NRT: (value is absent if not relevant to product) Near Real-Time identifier
* The mission identifier could be a reasonably shortened representation, e.g. Sentinel-3A = S3A
** The resolution element includes the units, e.g. 4km, 1deg
All PACE data available through NASA are fully and openly available without restriction.
For data distributed by NASA’s Ocean Biology Distributed Active Archive Center (OB.DAAC), use the reference notation of: Author, Release Date, Dataset Title, Publisher, doi reference, and date accessed.
Example:
NASA Ocean Biology Processing Group. (2018). Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) Level-2 Cloud Phase (daily), NASA Ocean Biology Distributed Active Archive Center. doi:XX.XXXX/XXXXX. Accessed on Month/day/year.
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