Abstract
Consistency in a time series of ocean colour satellite data is essential when determining long-term trends and statistics in Essential Climate Variables. For such a long time series, it is necessary to merge ocean colour data sets from different sensors due to the finite life span of the satellites. Although bias corrections have been performed on merged data set products, significant inconsistencies between missions remain. These inconsistencies appear as sudden steps in the time series of these products when a satellite mission is launched into- or removed from orbit. This inter-mission inconsistency is not caused by poor correction of sensor sensitivities but by differences in the ability of a sensor to observe certain waters. This study, based on a data set compiled by the ‘Ocean Colour Climate Change Initiative’ project (OC-CCI), shows that coastal waters, high latitudes, and areas subject to changing cloud cover are most affected by coverage variability between missions. The “Temporal Gap Detection Method” is introduced, which temporally homogenises the observations per-pixel of the time series and consequently minimises the magnitude of the inter-mission inconsistencies. The method presented is suitable to be transferred to other merged satellite-derived data sets that exhibit inconsistencies due to changes in coverage over time. The results provide insights into the correct interpretation of any merged ocean colour time series.
Original language | English |
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Article number | 882418 |
Journal | Frontiers in Remote Sensing |
Volume | 3 |
DOIs | |
Publication status | Published - 2022 |
Externally published | Yes |
Funding
This work is a contribution to the Ocean Colour Climate Change Initiative of the European Space Agency and was supported by the Helmholtz Association within the Earth and Environment research program. We would like to thank Arnold G. Dekker and the OC-CCI team for their valuable input and discussions. Thanks also to Geoffrey Bonning for his helpful suggestions. Finally, we would like to thank the reviewers for taking the time and effort to review the manuscript.
Funders | Funder number |
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Arnold G. Dekker | |
European Space Agency | |
Helmholtz Association |