Carbon Air–Sea Flux in the Arctic Ocean from CALIPSO from 2007 to 2020
Quantified research on the Arctic Ocean carbon system is poorly understood, limited by the scarce available data. Measuring the associated phytoplankton responses to air–sea CO2 fluxes is challenging using traditional satellite passive ocean color measurements due to low solar elevation angles. We c...
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ftmdpi:oai:mdpi.com:/2072-4292/14/24/6196/ 2023-08-20T04:03:27+02:00 Carbon Air–Sea Flux in the Arctic Ocean from CALIPSO from 2007 to 2020 Siqi Zhang Peng Chen Zhenhua Zhang Delu Pan agris 2022-12-07 application/pdf https://doi.org/10.3390/rs14246196 EN eng Multidisciplinary Digital Publishing Institute Environmental Remote Sensing https://dx.doi.org/10.3390/rs14246196 https://creativecommons.org/licenses/by/4.0/ Remote Sensing; Volume 14; Issue 24; Pages: 6196 diurnal variation air–sea carbon flux CALIPSO LiDAR remote sensing Text 2022 ftmdpi https://doi.org/10.3390/rs14246196 2023-08-01T07:41:21Z Quantified research on the Arctic Ocean carbon system is poorly understood, limited by the scarce available data. Measuring the associated phytoplankton responses to air–sea CO2 fluxes is challenging using traditional satellite passive ocean color measurements due to low solar elevation angles. We constructed a feedforward neural network light detection and ranging (LiDAR; FNN-LID) method to assess the Arctic diurnal partial pressure of carbon dioxide (pCO2) and formed a dataset of long-time-series variations in diurnal air–sea CO2 fluxes from 2001 to 2020; this study represents the first time spaceborne LiDAR data were employed in research on the Arctic air–sea carbon cycle, thus providing enlarged data coverage and diurnal pCO2 variations. Although some models replace Arctic winter Chl-a with the climatological average or interpolated Chl-a values, applying these statistical Chl-a values results in potential errors in the gap-filled wintertime pCO2 maps. The CALIPSO measurements obtained through active LiDAR sensing are not limited by solar radiation and can thus provide ‘fill-in’ data in the late autumn to early spring seasons, when ocean color sensors cannot record data; thus, we constructed the first complete record of polar pCO2. We obtained Arctic FFN-LID-fitted in situ measurements with an overall mean R2 of 0.75 and an average RMSE of 24.59 µatm and filled the wintertime observational gaps, thereby indicating that surface water pCO2 is higher in winter than in summer. The Arctic Ocean net CO2 sink has seasonal sources from some continental shelves. The growth rate of Arctic seawater pCO2 is becoming larger and more remarkable in sectors with significant sea ice retreat. The combination of sea surface partial pressure and wind speed impacts the diurnal carbon air–sea flux variability, which results in important differences between the Pacific and Atlantic Arctic Ocean. Our results show that the diurnal carbon sink is larger than the nocturnal carbon sink in the Atlantic Arctic Ocean, while the diurnal ... Text Arctic Arctic Ocean Atlantic Arctic Atlantic-Arctic Phytoplankton Sea ice MDPI Open Access Publishing Arctic Arctic Ocean Pacific Remote Sensing 14 24 6196 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
diurnal variation air–sea carbon flux CALIPSO LiDAR remote sensing |
spellingShingle |
diurnal variation air–sea carbon flux CALIPSO LiDAR remote sensing Siqi Zhang Peng Chen Zhenhua Zhang Delu Pan Carbon Air–Sea Flux in the Arctic Ocean from CALIPSO from 2007 to 2020 |
topic_facet |
diurnal variation air–sea carbon flux CALIPSO LiDAR remote sensing |
description |
Quantified research on the Arctic Ocean carbon system is poorly understood, limited by the scarce available data. Measuring the associated phytoplankton responses to air–sea CO2 fluxes is challenging using traditional satellite passive ocean color measurements due to low solar elevation angles. We constructed a feedforward neural network light detection and ranging (LiDAR; FNN-LID) method to assess the Arctic diurnal partial pressure of carbon dioxide (pCO2) and formed a dataset of long-time-series variations in diurnal air–sea CO2 fluxes from 2001 to 2020; this study represents the first time spaceborne LiDAR data were employed in research on the Arctic air–sea carbon cycle, thus providing enlarged data coverage and diurnal pCO2 variations. Although some models replace Arctic winter Chl-a with the climatological average or interpolated Chl-a values, applying these statistical Chl-a values results in potential errors in the gap-filled wintertime pCO2 maps. The CALIPSO measurements obtained through active LiDAR sensing are not limited by solar radiation and can thus provide ‘fill-in’ data in the late autumn to early spring seasons, when ocean color sensors cannot record data; thus, we constructed the first complete record of polar pCO2. We obtained Arctic FFN-LID-fitted in situ measurements with an overall mean R2 of 0.75 and an average RMSE of 24.59 µatm and filled the wintertime observational gaps, thereby indicating that surface water pCO2 is higher in winter than in summer. The Arctic Ocean net CO2 sink has seasonal sources from some continental shelves. The growth rate of Arctic seawater pCO2 is becoming larger and more remarkable in sectors with significant sea ice retreat. The combination of sea surface partial pressure and wind speed impacts the diurnal carbon air–sea flux variability, which results in important differences between the Pacific and Atlantic Arctic Ocean. Our results show that the diurnal carbon sink is larger than the nocturnal carbon sink in the Atlantic Arctic Ocean, while the diurnal ... |
format |
Text |
author |
Siqi Zhang Peng Chen Zhenhua Zhang Delu Pan |
author_facet |
Siqi Zhang Peng Chen Zhenhua Zhang Delu Pan |
author_sort |
Siqi Zhang |
title |
Carbon Air–Sea Flux in the Arctic Ocean from CALIPSO from 2007 to 2020 |
title_short |
Carbon Air–Sea Flux in the Arctic Ocean from CALIPSO from 2007 to 2020 |
title_full |
Carbon Air–Sea Flux in the Arctic Ocean from CALIPSO from 2007 to 2020 |
title_fullStr |
Carbon Air–Sea Flux in the Arctic Ocean from CALIPSO from 2007 to 2020 |
title_full_unstemmed |
Carbon Air–Sea Flux in the Arctic Ocean from CALIPSO from 2007 to 2020 |
title_sort |
carbon air–sea flux in the arctic ocean from calipso from 2007 to 2020 |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2022 |
url |
https://doi.org/10.3390/rs14246196 |
op_coverage |
agris |
geographic |
Arctic Arctic Ocean Pacific |
geographic_facet |
Arctic Arctic Ocean Pacific |
genre |
Arctic Arctic Ocean Atlantic Arctic Atlantic-Arctic Phytoplankton Sea ice |
genre_facet |
Arctic Arctic Ocean Atlantic Arctic Atlantic-Arctic Phytoplankton Sea ice |
op_source |
Remote Sensing; Volume 14; Issue 24; Pages: 6196 |
op_relation |
Environmental Remote Sensing https://dx.doi.org/10.3390/rs14246196 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/rs14246196 |
container_title |
Remote Sensing |
container_volume |
14 |
container_issue |
24 |
container_start_page |
6196 |
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1774713824557924352 |