NASA's Physical Oceanography Distributed Active Archive Center (PODAAC) generates the Multiscale Ultrahigh Resolution sea surface temperature (SST) product (version 4.1) that combines data from all current microwave and infrared polar-orbiting and geostationary satellites, including U.S. satellites and those of international partners such as Japan and Europe.

The satellite instruments vary on a daily basis depending on availability, but may include the following, among others:

• Advanced Microwave Scanning Radiometer-2 (AMSR-2) on Japan's GCOM-W1 satellite
• Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra and Aqua satellites
• WindSat on the U.S. Navy's Coriolis satellite
• Advanced Very High Resolution Radiometer (AVHRR) on NOAA's POES satellites and Europe's MetOp satellites

Nighttime skin and subskin SST observations from the available satellite instruments are blended (analyzed) using an optimal interpolation approach, called multi-resolution variational analysis (MRVA). The analysis technique includes in-situ SST observations from the NOAA iQuam project. As with data assimilation approaches, the in-situ SST observations are used in a bias correction to "nudge" the satellite SST's in the direction of the in-situ SST's for a more accurate analysis product. The number of included satellite instruments, and the analysis technique, allows for a daily, cloud-free, global product on a 0.01 degree grid (approximately 1 km).

The multi-resolution variational analysis method is based on wavelet decomposition. Its multi-scale design allows interpolation of the satellite pixel data at an optimal resolution for each data set, which is particularly useful for combining data sets from sensors with drastically different resolutions.

Near real-time SST data are generated by PODAAC with a 2-day delay, and retrospective science-quality SST data are generated with a 4-day delay.

NOAA CoastWatch East Coast Node obtains both the near real-time SST and retrospective science-quality SST from PODAAC. East Coast Node replaces the near real-time SST data files with the science-quality SST data files when they become available. Further, East Coast Node subsets the global data for the U.S. coasts. Currently, only U.S. east coast data files are made available through East Coast Node. In addition to daily files, monthly and annual mean composite files are available. East Coast Node distributes the entire time series of MUR SST data, from June 2002 to the present.

Figure: PODAAC MUR SST for July 30, 2015

The Multiscale Ultrahigh Resolution SST project is funded by the NASA MEaSUREs Program. More information may be found at the NASA Jet Propulsion Laboratory MUR project page.

Chin, T.M., J. Vazquez, and E. Armstrong. 2013. Algorithm Theorectical Basis Document: A multi-scale, high-resolution analysis of global sea surface temperature, Version 1.3. NASA Jet Propulsion Laboratory, Physical Oceanography Distributed Active Archive Center.