The PO.DAAC is pleased to announce the public release of the Integrated Multi-Mission Ocean Altimeter Sea Surface Height (SSH) Level 2 version 5.1 datasets, which are an extension of the NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) Program. More information regarding the MEaSUREs mission and instrumentations is available from PO.DAAC’s mission webpage. These datasets provide a coherent and consistent time series of Sea Surface Height (SSH) from multi-mission altimeter data, including TOPEX/Poseidon, Jason-1, OSTM/Jason-2, and Jason-3 missions covering the period of September 1992 to June 2021. In the near future, data from the Sentinel-6 Michael Freilich Jason CS mission will extend the time series. The development of the SSH Earth System Data Record (ESDR) was performed in part at NASA’s Goddard Space Flight Center, supported by NASA’s Physical Oceanography program. A portion of this work was carried out at the Jet Propulsion Laboratory.

Two datasets comprise this release: a single cycle SSH Level-2 version 5.1 (v5.1) and an integrated time series (all cycles) SSH Level-2 v5.1. The v5.1 data is updated from the previous v5.0 (DOI: https://doi.org/10.5067/ALTTS-TJA50 and https://doi.org/10.5067/ALTCY-TJA50) with extensive algorithm improvements and upgrades. The updates include implementation of Jason-3 GDR_F standards to several geophysical corrections, and file metadata upgrades. More information on data processing methodology can be found in the v5.1 User Handbook. Both of the datasets are in netCDF-4 format. Single cycle SSH v5.1 consists of one cycle of SSH, which is approximately 10 days long, while the time series SSH v5.1 combines all cycles into one single file. As more recent SSH data are processed, data extensions are appended to the datasets on a quarterly interval. The Integrated Multi-Mission Ocean Altimeter SSH v5.1 datasets are cloud-enabled and are described via the PO.DAAC dataset information pages with following DOIs.

DOI:

1. https://doi.org/10.5067/ALTCY-TJA51
2. https://doi.org/10.5067/ALTTS-TJA51

Access:

Users are encouraged to use the PO.DAAC Data downloader/subscriber (https://github.com/podaac/data-subscriber) to download the data. After installing the tool, the following command line example will download https://doi.org/10.5067/ALTCY-TJA51 into the chosen directory between the specified start and end dates (replace example dates with chosen dates):

# podaac-data-downloader -c MERGED_TP_J1_OSTM_OST_CYCLES_V51 -d YOUR_DIRECTORY -sd 2021-05-01T00:00:00Z -ed 2021-05-03T00:00:00Z

Comments/Questions? Please contact podaac@podaac.jpl.nasa.gov or visit the PO.DAAC Forum.