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    • NASA-SSH IOD Sea Surface Height Indicator

    Metadata Updated: September 18, 2025

    This file contains an indicator for the Indian Ocean Dipole (IOD), based on satellite observations of sea surface height anomaly, measured by radar altimeter missions such as TOPEX/Poseidon, the Jason series, and Sentinel-6. The indicator values were calculated using NASA-SSH Simple Gridded Sea Surface Height from Standardized Reference Missions Only Version 1 https://podaac.jpl.nasa.gov/dataset/NASA_SSH_REF_SIMPLE_GRID_V1 . Indicator values were calculated using cyclostationary empirical orthogonal functions (CSEOFs; Kim et al., 2015) computed by decomposing the gridded sea surface height anomalies over the time period from 1993 to 2019. After removing the linear trend from each individual gridded location, three sets of regional CSEOFs were generated, one each for the El Nino-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) and (IOD). In each case, the dominant statistical mode represents the seasonal cycle. The second most dominant mode represents the variability explained by each respective indicator and is referred to as the “indicator mode”. The seasonal mode and indicator mode are then projected onto the along-track sea surface height anomalies to produce the indicator time series through the most current date. In this case, the IOD mode was used to produce the time series contained in this file. The file with the filename "NASA_SSH_IOD_INDICATOR.txt" is always the most up-to-date time series containing the most recent data.

    Access & Use Information

    Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Created Date April 29, 2025
    Metadata Updated Date September 18, 2025

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date April 29, 2025
    Metadata Updated Date September 18, 2025
    Publisher NASA/JPL/PODAAC
    Maintainer
    Identifier 10.5067/NSIND-IODV1
    Data Last Modified 2025-09-11
    Category Earth Science
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Harvest Object Id 0aaf10c6-c5f2-462c-8e7d-5b38ad575ef1
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://search.earthdata.nasa.gov/search/granules?p=C3478941029-POCLOUD
    Old Spatial {"NorthBoundingCoordinate":66,"SouthBoundingCoordinate":-66,"EastBoundingCoordinate":180,"WestBoundingCoordinate":-180},"CARTESIAN"
    Program Code 026:000
    Source Datajson Identifier True
    Source Hash 4048bc039a7ad9a829c16581e9c5dcea72747a14a5eadc8f8a8316612813cea7
    Source Schema Version 1.1
    Spatial
    Temporal 1993-01-04/1993-01-04

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