NASA deploys a number of Earth observing instruments that measure the spectral nature, or color, of water. Specifically, NASA acquires, archives, and publicly distributes such data from a variety of sources, including remote sensing ocean color instruments on satellite and airborne platforms, as well as similar measurements made on shipborne field campaigns, by long-duration autonomous in situ platforms, and derived as Earth system model outputs.
The Ocean Biology Processing Group (OBPG) at NASA's Goddard Space Flight Center has been operating and supporting the Ocean Color Web since 1996. As a Science Investigator-led Processing System (SIPS), our responsibilities include the collection, processing, calibration, validation of ocean-related products from a large number of operational, satellite-based remote-sensing missions providing ocean color, sea surface temperature and sea surface salinity data to the international research community. As a Distributed Active Archive Center (DAAC), known as the Ocean Biology DAAC (OB.DAAC), we are responsible for the archive and distribution of satellite ocean biology data produced or collected under NASA EOSDIS, including those from historical missions and partner space organizations.
Ocean Color is the apparent hue, shade, or tone of water that results from the interactions of sunlight with the microscopic composition of the water column and water itself. Typical relevant water constituents include phytoplankton, mineral particles, and dissolved organic matter. The color of the ocean varies with how these materials in seawater absorb and scatter photons of different wavelengths, which varies with their composition. For example, highly productive waters where phytoplankton are abundant can appear green, whereas less productive waters with fewer constituents typically appear blue.
The spectral nature of color of the water, that is, the intensity at which different wavelengths absorb and scatter photons, can be used to infer the quality and quantity of materials that comprise natural waters - allowing scientists, policymakers, and society as a whole to understand their composition on local to global scales. This understanding can lend insight into how aquatic organisms at the base of the food chain thrive or decline under changing conditions of their environments.
PACE is NASA's Plankton, Aerosol, Cloud, ocean Ecosystem mission, currently in the design phase of mission development. It is scheduled to launch in 2024, extending and improving NASA's over 20-year record of satellite observations of global ocean biology, aerosols (tiny particles suspended in the atmosphere), and clouds.
PACE will advance the assessment of ocean health by measuring the distribution of phytoplankton, tiny plants and algae that sustain the marine food web. It will also continue systematic records of key atmospheric variables associated with air quality and Earth's climate.
PACE has two fundamental science goals:
