LETKF-based Ocean Research Analysis (LORA)

  • DOI: 10.57746/EO.01hc1e0qpr8z5jmn7cnwwrf3j5
  • Last Updated: 2025-01-31

Product Summary

JAXA and RIKEN aim to unify satellite data (AMSR2, Himawari, etc.) and ocean simulation and create an ensemble ocean analysis product, LETKF-based Ocean Research Analysis (LORA), by assimilating satellite and in-situ observations from JAXA and various institutions at a 1-day interval in a high-resolution regional ocean data assimilation system, sbPOM-LETKF, developed by RIKEN. LORA has the advantages of 1) being a three-dimensional gridded dataset without missing values, 2) having high accuracy especially in the mid-latitude regions, and 3) quantifying uncertainty. The uncertainty is estimated from the standard deviation of 128 ensemble members (i.e., ensemble spread). In addition to the daily averaged ensemble mean and spread of basic variables, LORA provides daily-averaged all ensemble members at the sea surface and ensemble mean of each term in mixed-layer temperature and salinity budget equations, respectively, to be utilized for boundary conditions in atmospheric models and for quantitative analyses of spatiotemporal variations in sea surface temperatures and salinity.
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Version, Release date, Availability
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Ver.1.0, 2023-3-31, Available

Platform
Model
Sensor
N/A

Coverage

Temporal Coverage

2015-08-01 to 2024-01-31

Spatial Coverage

Bounding Rectangle
WNP (red) (50.0°, 108.0°, 12.0°, 180.0°) 
MC (blue) (30.0°, 95.0°, -18.0°, 136.0°)  

Resolution

0.1 degree

Location

  • NORTHWEST PACIFIC OCEAN, WESTERN PACIFIC OCEAN
Dataset Short Name
LETKF-based_Ocean_Research_Analysis_(LORA)
Platform / Sensor
Model / N/A
Coverage
Spatial Coverage
Bounding Rectangle
WNP (Western North Pacific) (50.0°, 108.0°, 12.0°, 180.0°),
MC (Maritime Continent) (30.0°, 95.0°, -18.0°, 136.0°)
Temporal Coverage
2015-08-01 to 2024-01-31
Product Level ID
L4
Version Description

Ver.1.0

File Format
NetCDF
Dataset Type
Daily average / frame
Resolution
Spatial Resolution
0.1 degree
Temporal Resolution
Daily
Dataset Progress
In Work
Projection
Equal Latitude-Longitude grid (Arakawa-C)
Collection Data Type
SCIENCE_QUALITY
Get Data
https://www.eorc.jaxa.jp/ptree/LORA/index.html
Dataset Title
LETKF-based Ocean Research Analysis (LORA)
Distribution Format
NetCDF
Fees
Free
Citation
Ohishi et al., 2024: https://doi.org/10.1002/gdj3.271

Ohishi et al., 2023: https://link.springer.com/article/10.1007/s10236-023-01541-3
Japan Aerospace Exploration Agency, 2015: LETKF-based Ocean Research Analysis (LORA). https://doi.org/10.57746/EO.01hc1e0qpr8z5jmn7cnwwrf3j5
Access Constraints

Use of the data provided by this system is limited to non-profit purposes such as research and education. Users need to register at the JAXA Himawari Monitor (https://www.eorc.jaxa.jp/ptree/registration_top.html) to get account for downloading.

Use Constraints

Users cannot redistribute the data to the third parties. Conditions of data use are described in registration page (https://www.eorc.jaxa.jp/ptree/registration_top.html) and Section 3 “Reporting requirement” of User Guide (https://www.eorc.jaxa.jp/ptree/userguide.html). Users should specify the following sentence when they publish a thesis, a report, and so on by using the dataset. “Ocean model product that was used in this paper was jointly developed by the Japan Aerospace Exploration Agency (JAXA) and RIKEN and supplied by the JAXA P-Tree System.”

P-Tree Terms of service
https://www.eorc.jaxa.jp/ptree/registration_top.html
ISO Topic Categories
  • OCEANS
Science Keywords
  • EARTH SCIENCE > OCEANS
  • EARTH SCIENCE SERVICES > MODELS > OCEAN GENERAL CIRCULATION MODELS (OGCM)/REGIONAL OCEAN MODELS
Location Keywords
  • GEOGRAPHIC REGION > OCEAN > PACIFIC OCEAN > NORTHWEST PACIFIC OCEAN, WESTERN PACIFIC OCEAN
ECV and other Keywords
  • ocean temperature
  • salinity
  • current

ISO Topic Categories is the keywords in the ISO 19115 - Geographic Information Metadata.

Science Keywords hosts Global Change Master Directory (GCMD) Keywords which are a hierarchical set of controlled Earth Science vocabularies that help ensure Earth science data, services, and variables are described in a consistent and comprehensive manner and allow for the precise searching of metadata and subsequent retrieval of data, services, and variables.

ECV Keywords hosts a physical, chemical or biological variable or a group of linked variables that critically contributes to the characterization of Earth's climate.