Chlorophyll and POC in polar regions derived from spaceborne lidar
Polar regions have the most productive ecosystems in the global ocean but are vulnerable to global climate changes. Traditionally, the long-term changes occurred in an ecosystem are studied by using satellite-derived estimates of passive ocean color remote sensing measurements. However, this technol...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-02-01
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| Series: | Frontiers in Marine Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2023.1050087/full |
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| author | Zhenhua Zhang Zhenhua Zhang Peng Chen Peng Chen Chunyi Zhong Congshuang Xie Miao Sun Siqi Zhang Su Chen Danchen Wu |
| author_facet | Zhenhua Zhang Zhenhua Zhang Peng Chen Peng Chen Chunyi Zhong Congshuang Xie Miao Sun Siqi Zhang Su Chen Danchen Wu |
| author_sort | Zhenhua Zhang |
| collection | DOAJ |
| description | Polar regions have the most productive ecosystems in the global ocean but are vulnerable to global climate changes. Traditionally, the long-term changes occurred in an ecosystem are studied by using satellite-derived estimates of passive ocean color remote sensing measurements. However, this technology is severely limited by the inability to observe high-latitude ocean areas during lengthy polar nights. The spaceborne lidar can address the limitations and provide a decade of uninterrupted polar observations. This paper presents an innovative feed-forward neural network (FFNN) model for the inversion of subsurface particulate backscatter coefficients (bbp), chlorophyll concentration (Chl), and total particulate organic carbon (POC) from the spaceborne lidar. Non-linear relationship between lidar signal and bio-optical parameters was estimated through FFNN. The inversion results are in good agreement with biogeochemical Argo data, indicating the accuracy of the method. The annual cycles of Chl and POC were then analyzed based on the inversion results. We find that Chl, bbp, and POC have similar interannual variability but there are some subtle differences between them. Light limitation appears to be a dominant factor controlling phytoplankton growth in polar regions according to the results. Overall, the combined analysis of bbp, Chl, and POC contributes to a comprehensive understanding of interannual variability in the ecosystem in polar regions. |
| first_indexed | 2024-04-10T17:44:01Z |
| format | Article |
| id | doaj.art-32e40485455b4a10a6b069fd480d5a3e |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-04-10T17:44:01Z |
| publishDate | 2023-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-32e40485455b4a10a6b069fd480d5a3e2023-02-03T05:27:50ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452023-02-011010.3389/fmars.2023.10500871050087Chlorophyll and POC in polar regions derived from spaceborne lidarZhenhua Zhang0Zhenhua Zhang1Peng Chen2Peng Chen3Chunyi Zhong4Congshuang Xie5Miao Sun6Siqi Zhang7Su Chen8Danchen Wu9Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, ChinaState Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, ChinaSouthern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, ChinaState Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, ChinaState Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, ChinaState Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, ChinaState Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, ChinaState Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, ChinaState Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, ChinaState Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, ChinaPolar regions have the most productive ecosystems in the global ocean but are vulnerable to global climate changes. Traditionally, the long-term changes occurred in an ecosystem are studied by using satellite-derived estimates of passive ocean color remote sensing measurements. However, this technology is severely limited by the inability to observe high-latitude ocean areas during lengthy polar nights. The spaceborne lidar can address the limitations and provide a decade of uninterrupted polar observations. This paper presents an innovative feed-forward neural network (FFNN) model for the inversion of subsurface particulate backscatter coefficients (bbp), chlorophyll concentration (Chl), and total particulate organic carbon (POC) from the spaceborne lidar. Non-linear relationship between lidar signal and bio-optical parameters was estimated through FFNN. The inversion results are in good agreement with biogeochemical Argo data, indicating the accuracy of the method. The annual cycles of Chl and POC were then analyzed based on the inversion results. We find that Chl, bbp, and POC have similar interannual variability but there are some subtle differences between them. Light limitation appears to be a dominant factor controlling phytoplankton growth in polar regions according to the results. Overall, the combined analysis of bbp, Chl, and POC contributes to a comprehensive understanding of interannual variability in the ecosystem in polar regions.https://www.frontiersin.org/articles/10.3389/fmars.2023.1050087/fullchlorophyllbbpPOCCALIOPpolar oceansphytoplankton |
| spellingShingle | Zhenhua Zhang Zhenhua Zhang Peng Chen Peng Chen Chunyi Zhong Congshuang Xie Miao Sun Siqi Zhang Su Chen Danchen Wu Chlorophyll and POC in polar regions derived from spaceborne lidar Frontiers in Marine Science chlorophyll bbp POC CALIOP polar oceans phytoplankton |
| title | Chlorophyll and POC in polar regions derived from spaceborne lidar |
| title_full | Chlorophyll and POC in polar regions derived from spaceborne lidar |
| title_fullStr | Chlorophyll and POC in polar regions derived from spaceborne lidar |
| title_full_unstemmed | Chlorophyll and POC in polar regions derived from spaceborne lidar |
| title_short | Chlorophyll and POC in polar regions derived from spaceborne lidar |
| title_sort | chlorophyll and poc in polar regions derived from spaceborne lidar |
| topic | chlorophyll bbp POC CALIOP polar oceans phytoplankton |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2023.1050087/full |
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