Global oceans data

PACE Particulate Backscattering March 2024 – present (8 Day Average)

Particulate backscattering coefficient at 442 nanometers (bbp (442)) from the NASA Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) Ocean Color Instrument (OCI). This bbp (442) data layer provides a proxy of water clarity overall as well as an estimate of suspended particulate constituents present in the water. bbp (442) is provided as global, 8-day averages mapped to a standard, equal-angle, latitude-longitude grid of approximately 0.04 degrees, or 4 kilometers (km) at the equator. Pixels with no data values are masked (excluded) due to presence of land, cloud cover, or other features marked by quality control flags as described below. Data Layer Summary Name, units Particulate Backscattering at 442 nm [m-1] Backscattering coefficient of suspended particulate material at 442 nm in units of inverse meters (m-1) Spatial resolution 4 km2 Level-3, mapped to standard grid, global coverage Time Resolution 8 day average Each pixel represents an average of the valid, daily values observed within that grid element during the 8-day interval (approx 1 week). Note: 8 day average data layer is calculated from daily, "refined" (archive-quality) Level 3 PACE bbp (442) products, which are available at NASA Earthdata via this link in NetCDF format as part of the Inherent Optical Properties (IOP) suite. NASA Earthdata account required to download. Data Version Version 3.2 Data versions change as improved calibration, validation, algorithm refinements, etc are applied over time. See Version 3.2 Release Notes for details. Latency ̃1 month This imagery service provides “refined” (archive-quality) PACE data products from March 2024-present, which have an approx 1 month latency. Note: Lower latency “near real time (NRT)” Level 3 PACE bbp (442) data are available at NASA Earthdata via this link in NetCDF format as part of the Inherent Optical Properties (IOP) NRT suite. Latency typically account required to download. What can I do with this layer? The bbp (442) data layer supports water-type classification, water-clarity assessment, biogeochemical studies, and forward/adjoint radiative-transfer applications. As an inherent optical property (IOP, described in background information below), bbp (442) is more suitable for cross-sensor comparisons than apparent optical property (AOP) measurements, which vary with solar conditions at the time of measurement. The time (8 day average) and space (4 km2) resolution of this data layer enables weekly to seasonal and annual insight at sub-regional to global scales. What should I know about the data? Data Status (Maturity): This product is provisional, which means that product results have been reviewed and are in family with heritage data products or other basis of expectation, but have not yet been extensively validated and so may still contain significant errors. Data layer is sufficient for qualitative determinations of product fitness-for-purpose, for testing by operational users, and may be suitable for scientific publication. Data Masking: These products are Level 3, globally-binned products from NASA’s Ocean Biology Processing Group (OBPG), which by default are masked (pixel data value is set to null, or no data) according to a standard set of quality control parameters. For a list of these parameters, see the third column of the table included here: https://oceancolor.gsfc.nasa.gov/resources/atbd/ocl2flags/. Application of bbp (442) in varied water types: The Generalized Inherent Optical Properties framework in its default algorithm configuration (GIOP-DC; Werdell et al. 2013) used to derive bbp (442) was developed to maximize global performance. End users are advised to carefully consider the validity of retrievals in extreme conditions such as highly turbid, optically shallow, and inland/freshwater systems where values may carry higher uncertainty. Algorithm Theoretical Basis Document (ATBD): See ATBD for algorithm details including scientific theory, calculations, etc. at DOI 10.5067/ZGBW3QECROJ2. Where do I go with further questions? Visit NASA’s Earthdata Forum where users can post questions that are answered by the personnel working at NASA with the PACE mission and/or the Ocean Biology Distributed Active Archive Center (OB.DAAC) that processes and distributes PACE data. First, follow this link to view only “PACE” and “OBDAAC” tagged questions on the Earthdata Forum. Then search and read through previous posts for your question. If it has not yet been asked please post your question in the Forum and be sure "PACE" and "OBDAAC" filter tags are applied. Mission and Product Background PACE Mission Overview: Launched in February 2024, NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) observatory uniquely provides near-daily, hyperspectral coverage of Earth’s surface, plus hyperspectral and hyperangular polarimetry. PACE is a comprehensive Earth System mission, delivering all new, space-based information on the health and diversity of aquatic and terrestrial life (algae, plants), aerosol properties & modes (e.g. smoke, dust), cloud types, and more. The Ocean Color Instrument (OCI), PACE's primary sensor, is a hyperspectral (5 nm resolution) imaging spectrometer that measures properties of light from the ultraviolet (UV, 340 nm) through visible and near infrared (NIR, 895 nm) portions of the electromagnetic spectrum in 1.25 to 2.5 nm steps, plus 7 shortwave infrared (SWIR) bands (Werdell et al. 2019). Observations from OCI are moderate spatial resolution (1.2 km2), enabling a relatively frequent revisit time of 1-2 days. This combination of continuous, global coverage and spectral capabilities is unmatched by any other satellite platform, public or private. PACE benefits society by expanding our foundational knowledge of Earth and enabling novel, space-based science and applications tools across water resources (e.g. fisheries), air quality, land monitoring & management, and more. The Ocean Color Instrument (OCI), PACE’s primary sensor, is a hyperspectral (5 nm resolution) imaging spectrometer that measures properties of light from the ultraviolet (UV, 340 nm) through visible and near infrared (NIR, 895 nm) portions of the electromagnetic spectrum, plus 7 shortwave infrared (SWIR) bands (Werdell et al. 2019). Observations from OCI are moderate spatial resolution (1.2 km2), enabling a relatively frequent revisit time of 1-2 days. This combination of continuous, global coverage and spectral capabilities is unmatched by any other satellite platform, public or private. PACE benefits society by expanding our foundational knowledge of Earth and enabling novel, space-based science and applications tools across water resources (e.g. fisheries), air quality, land monitoring & management, and more. How is bbp (442) calculated and what does it represent? Inherent optical properties (IOPs; spectral absorption and backscattering coefficients) help us understand how different wavelengths (colors) of light are scattered and absorbed by materials present in natural waters such as lakes, coastal waters, and the ocean. Unlike apparent optical properties (AOPs), IOPs are independent of the surrounding light field or viewing geometry. The different constituents in natural waters - including the water itself, phytoplankton, dissolved matter, and non-algal particulate matter - absorb and scatter light in different ways due to factors such as shape, size, and pigmentation. The types and relative concentrations of constituent matter drive the character of the light reflected from the water making IOPs key parameters in understanding marine biogeochemical processes and the characteristics of the under-water light field. The current default configuration of the Generalized Inherent Optical Properties (GIOP-DC; Werdell et al. 2013) algorithm used to derive this data layer is based on a scientific understanding of the physics of light in water, relating IOPs to the light reflected from the ocean that is observed by space-borne sensors. The GIOP-DC input variables include spectral remote sensing reflectance values and biophysical environmental conditions, and returned variables include 7 atmospherically corrected spectral IOPs of near surface waters and their uncertanty values (see ATBD for details). Of these GIOP-DC output variables, the coefficients of both particulate bacscattering and non-algal particulate plus colored dissolved organic matter at one wavelength of 442 nm (bbp (455) and adg (442), respectively, in units of meters-1) are provided here as data layers to utilize as measures of the absorption and scattering properties of a given water body. What other PACE data layers are available? This data layer is 1 of 11 PACE products initially selected for the Living Atlas catalog from the mission’s comprehensive aquatic, atmospheric, and terrestrial product catalog. Click here to view all 11 PACE Living Atlas imagery services. Global, hyperspectral remote sensing reflectance observations from OCI with over 250 spectral bands, and used to derive many of PACE's aquatic products, are available to download in NetCDF format from NASA Earthdata as Level 3, mapped data with 4 km2 resolution or as Level 2 granules at unprojected, native spatial resolution (1.2 km2). To learn more about obtaining PACE data from NASA, first learn about PACE data access here, next decide which product(s) you would like to use, then go to NASA Earthdata to find your product(s) of interest in NetCDF format, which can be downloaded and then imported into ArcGIS. To learn about using Earthdata Search to narrow your data product selection, watch this tutorial. An Earthdata account is needed to download data from NASA, sign up here. How can I stay up to date with the PACE mission? Join the PACE Community for mission news, events, new product release announcements, and to receive our newsletters. Would you like to see imagery services for more PACE products? Please let us know here. References: McKinna, L. & Werdell, J., authors. (2024) Algorithm theoretical basis document: Inherent Optical Properties, Version 1.0. NASA Goddard Space Flight Center, Ocean Ecology Lab. https://doi.org/10.5067/JCQB8QALDOYD. Werdell, P. J., Franz, B. A., Bailey, S. W., Feldman, G. C., Boss, E., Brando, V. E., Dowell, M. et al. (2013) Generalized ocean color inversion model for retrieving marine inherent optical properties. Applied Optics, 52(10), 2019--2037. https://doi.org/10.1364/AO.52.002019 Werdell, P. J. et al. (2019) The Plankton, Aerosol, Cloud, Ocean Ecosystem Mission: Status, Science, Advances. Bulletin of the American Meteorological Society, 100, 1775–1794. https://doi.org/10.1175/BAMS-D-18-0056.1

Oceans · NASA_Earthdata