NASA-SSH PDO Sea Surface Height Indicator

(NASA_SSH_PDO_INDICATOR)
Version1
Processing Level4
Start/Stop Date1993-Jan-04 to Present
Short NameNASA_SSH_PDO_INDICATOR
DescriptionThis file contains an indicator for the Pacific Decadal Oscillation (PDO), 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 El Nino-Southern Oscillation (ENSO), the PDO and Indian Ocean Diode (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 PDO mode was used to produce the time series contained in this file.

The file with the filename "NASA_SSH_PDO_INDICATOR.txt" is always the most up-to-date time series containing the most recent data.
DOI10.5067/NSIND-PDOV1
MeasurementOCEANS > SEA SURFACE TOPOGRAPHY > SEA LEVEL
OCEANS > SEA SURFACE TOPOGRAPHY > SEA SURFACE HEIGHT
Platform/Sensor
TOPEX/POSEIDON
Platform
Name: Ocean Topography Experiment (TOPEX/POSEIDON)
/
SSALT
SENSOR
Name: POSEIDON Solid State Radar Altimeter (SSALT)

TOPEX/POSEIDON
Platform
Name: Ocean Topography Experiment (TOPEX/POSEIDON)
/
NRA
SENSOR
Name: Nasa Radar Altimeter (NRA)

TOPEX/POSEIDON
Platform
Name: Ocean Topography Experiment (TOPEX/POSEIDON)
/
TMR
SENSOR
Name: TOPEX Microwave Radiometer (TMR)

JASON-1
Platform
Name: Ocean Topography Experiment (JASON-1)
/
POSEIDON-2
SENSOR
Name: JASON-1 RADAR ALTIMETER (POSEIDON-2)

JASON-1
Platform
Name: Ocean Topography Experiment (JASON-1)
/
JASON-1 Microwave Radiometer
SENSOR
Name: JASON-1 Microwave Radiometer (JASON-1 Microwave Radiometer)

OSTM/JASON-2
Platform
Name: Joint Altimetry Satellite Oceanography Network - 2 (OSTM/JASON-2)
/
POSEIDON-3
SENSOR
Name: JASON-2 RADAR ALTIMETER (POSEIDON-3)

OSTM/JASON-2
Platform
Name: Joint Altimetry Satellite Oceanography Network - 2 (OSTM/JASON-2)
/
AMR
SENSOR
Name: Advanced Microwave Radiometer (AMR)

JASON-3
Platform
Name: Joint Altimetry Satellite Oceanography Network - 3 (JASON-3)
/
POSEIDON-3B
SENSOR
Name: Poseidon-3B Altimeter (POSEIDON-3B)

JASON-3
Platform
Name: Joint Altimetry Satellite Oceanography Network - 3 (JASON-3)
/
AMR-2
SENSOR
Name: Advanced Microwave Radiometer-2 (AMR-2)

Sentinel-6A
Platform
Name: Sentinel-6A (Sentinel-6A)
/
Poseidon-4 Radar Altimeter
SENSOR
Name: Poseidon-4 Radar Altimeter (Poseidon-4 Radar Altimeter)

Sentinel-6A
Platform
Name: Sentinel-6A (Sentinel-6A)
/
AMR-C
SENSOR
Name: Advanced Microwave Radiometer-C (AMR-C)

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ProjectNASA Sea Surface Height Products based on Radar Altimetry (NASA-SSH)
Data ProviderPublisher: PO.DAAC
Creator: Willis, J. K., S. Fournier, K. Marlis, and E. Killett
Release Place: CA, USA
Release Date: 2025-Apr-19

FormatASCII
Keyword(s)ENSO, El Nino, La Nina, El Nino - Southern Oscillation
Questions related to this dataset? Contact podaac@podaac.jpl.nasa.gov
Resolution
Temporal Resolution: Weekly - < Monthly
 
Coverage
North Bounding Coordinate: 66 degrees
South Bounding Coordinate: -66 degrees
West Bounding Coordinate: -180 degrees
East Bounding Coordinate: 180 degrees
Time Span: 1993-Jan-04 to Present
 
USER'S GUIDE
GENERAL DOCUMENTATION
USER FEEDBACK PAGE
DATA CITATION GUIDELINES
Citation is critically important for dataset documentation and discovery. Please cite the data as follows, and cite the reference papers when it is appropriate.
Citation Willis, J. K., S. Fournier, K. Marlis, and E. Killett. 2025. NASA-SSH PDO Sea Surface Height Indicator. Ver. 1. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at https://doi.org/10.5067/NSIND-PDOV1

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For more information see Data Citations and Acknowledgments.
Journal Reference K.Y. Kim, B. Hamlington, H. Na. 2015. Theoretical foundation of cyclostationary EOF analysis for geophysical and climatic variables: concepts and examples, Elsevier, 150. 10.1016/j.earscirev.2015.06.003

P. Kumar, B. Hamlington, S. Cheon, W. Han, and P. Thompson. 2020. 20th Century Multivariate Indian Ocean Regional Sea Level Reconstruction,, 125, 10. 10.1029/2020jc016270

B. D. Hamlington et al.. 2019. The Dominant Global Modes of Recent Internal Sea Level Variability,, 124 , 4. 10.1029/2018jc014635