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Estimating and validating instantaneous PAR from GOCI-I data.

Deuk-Jae Hwang, Robert Frouin, Jing Tan

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    PubMed
    Summary
    This summary is machine-generated.

    Geostationary-orbit sensors like GOCI-I accurately estimate instantaneous photosynthetically available radiation (iPAR) in the ocean around Korea. This data is crucial for understanding daily primary production and carbon cycling in the region.

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    Area of Science:

    • Oceanography
    • Remote Sensing
    • Biogeochemistry

    Background:

    • Geostationary sensors offer high-frequency ocean observations vital for studying short-term dynamics.
    • Daily primary production (PP) is key to carbon cycle analysis, necessitating regional-scale daily change assessments.
    • Estimating instantaneous PP (iPP) requires accurate instantaneous photosynthetically available radiation (iPAR) data.

    Purpose of the Study:

    • To estimate iPAR using the GOCI-I sensor over the ocean around the Korean Peninsula.
    • To validate GOCI-I iPAR estimates against in-situ measurements.
    • To compare GOCI-I iPAR accuracy with other satellite sensors like AHI and MODIS.

    Main Methods:

    • A plane-parallel theory-based PAR model was used to estimate iPAR from GOCI-I data.
    • In-situ iPAR measurements from ECO-PAR sensors (2015-2020) were used for training and validation.
    • In-situ data were corrected using radiative transfer simulations and polynomial regression.

    Main Results:

    • GOCI-I iPAR estimates showed good agreement with corrected in-situ data (RMSE: 10.36%, MBE: 1.55% for 2015-2017; RMSE: 10.04%, MBE: 0.74% for 2018-2020).
    • GOCI-I iPAR demonstrated higher accuracy (lower RMSE and MBE, higher R²) compared to AHI and MODIS iPAR.
    • The study confirms GOCI-I's capability in capturing diurnal iPAR variability.

    Conclusions:

    • GOCI-I provides a valuable dataset for assessing diurnal oceanic PP variability around the Korean Peninsula.
    • Accurate iPAR estimation from GOCI-I supports improved regional carbon cycle studies.
    • This research highlights the utility of geostationary sensors for detailed oceanographic monitoring.