A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean
The ability to construct nitrate maps in the Southern Ocean (SO) from sparse observations is important for marine biogeochemistry research, as it offers a geographical estimate of biological productivity. The goal of this study is to infer the skill of constructed SO nitrate maps using varying data...
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ftcdlib:oai:escholarship.org:ark:/13030/qt6zv402vr 2023-10-01T03:59:35+02:00 A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean Liang, Yu-Chiao Mazloff, Matthew R Rosso, Isabella Fang, Shih-Wei Yu, Jin-Yi 1505 - 1519 2018-01-01 application/pdf https://escholarship.org/uc/item/6zv402vr unknown eScholarship, University of California qt6zv402vr https://escholarship.org/uc/item/6zv402vr CC-BY Journal of Atmospheric and Oceanic Technology, vol 35, iss 7 Life Below Water Sampling Empirical orthogonal functions Ocean models Atmospheric Sciences Oceanography Maritime Engineering Meteorology & Atmospheric Sciences article 2018 ftcdlib 2023-09-04T18:04:49Z The ability to construct nitrate maps in the Southern Ocean (SO) from sparse observations is important for marine biogeochemistry research, as it offers a geographical estimate of biological productivity. The goal of this study is to infer the skill of constructed SO nitrate maps using varying data sampling strategies. The mapping method uses multivariate empirical orthogonal functions (MEOFs) constructed from nitrate, salinity, and potential temperature (N-S-T) fields from a biogeochemical general circulation model simulation Synthetic N-S-T datasets are created by sampling modeled N-S-T fields in specific regions, determined either by random selection or by selecting regions over a certain threshold of nitrate temporal variances. The first 500 MEOF modes, determined by their capability to reconstruct the original N-S-T fields, are projected onto these synthetic N-S-T data to construct time-varying nitrate maps. Normalized root-mean-square errors (NRMSEs) are calculated between the constructed nitrate maps and the original modeled fields for different sampling strategies. The sampling strategy according to nitrate variances is shown to yield maps with lower NRMSEs than mapping adopting random sampling. A k-means cluster method that considers the N-S-T combined variances to identify key regions to insert data is most effective in reducing the mapping errors. These findings are further quantified by a series of mapping error analyses that also address the significance of data sampling density. The results provide a sampling framework to prioritize the deployment of biogeochemical Argo floats for constructing nitrate maps. Article in Journal/Newspaper Southern Ocean University of California: eScholarship Southern Ocean |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Life Below Water Sampling Empirical orthogonal functions Ocean models Atmospheric Sciences Oceanography Maritime Engineering Meteorology & Atmospheric Sciences |
spellingShingle |
Life Below Water Sampling Empirical orthogonal functions Ocean models Atmospheric Sciences Oceanography Maritime Engineering Meteorology & Atmospheric Sciences Liang, Yu-Chiao Mazloff, Matthew R Rosso, Isabella Fang, Shih-Wei Yu, Jin-Yi A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean |
topic_facet |
Life Below Water Sampling Empirical orthogonal functions Ocean models Atmospheric Sciences Oceanography Maritime Engineering Meteorology & Atmospheric Sciences |
description |
The ability to construct nitrate maps in the Southern Ocean (SO) from sparse observations is important for marine biogeochemistry research, as it offers a geographical estimate of biological productivity. The goal of this study is to infer the skill of constructed SO nitrate maps using varying data sampling strategies. The mapping method uses multivariate empirical orthogonal functions (MEOFs) constructed from nitrate, salinity, and potential temperature (N-S-T) fields from a biogeochemical general circulation model simulation Synthetic N-S-T datasets are created by sampling modeled N-S-T fields in specific regions, determined either by random selection or by selecting regions over a certain threshold of nitrate temporal variances. The first 500 MEOF modes, determined by their capability to reconstruct the original N-S-T fields, are projected onto these synthetic N-S-T data to construct time-varying nitrate maps. Normalized root-mean-square errors (NRMSEs) are calculated between the constructed nitrate maps and the original modeled fields for different sampling strategies. The sampling strategy according to nitrate variances is shown to yield maps with lower NRMSEs than mapping adopting random sampling. A k-means cluster method that considers the N-S-T combined variances to identify key regions to insert data is most effective in reducing the mapping errors. These findings are further quantified by a series of mapping error analyses that also address the significance of data sampling density. The results provide a sampling framework to prioritize the deployment of biogeochemical Argo floats for constructing nitrate maps. |
format |
Article in Journal/Newspaper |
author |
Liang, Yu-Chiao Mazloff, Matthew R Rosso, Isabella Fang, Shih-Wei Yu, Jin-Yi |
author_facet |
Liang, Yu-Chiao Mazloff, Matthew R Rosso, Isabella Fang, Shih-Wei Yu, Jin-Yi |
author_sort |
Liang, Yu-Chiao |
title |
A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean |
title_short |
A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean |
title_full |
A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean |
title_fullStr |
A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean |
title_full_unstemmed |
A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean A Multi-variate Empirical Orthogonal Function Method to Construct Nitrate Maps in the Southern Ocean |
title_sort |
multi-variate empirical orthogonal function method to construct nitrate maps in the southern ocean a multi-variate empirical orthogonal function method to construct nitrate maps in the southern ocean |
publisher |
eScholarship, University of California |
publishDate |
2018 |
url |
https://escholarship.org/uc/item/6zv402vr |
op_coverage |
1505 - 1519 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Journal of Atmospheric and Oceanic Technology, vol 35, iss 7 |
op_relation |
qt6zv402vr https://escholarship.org/uc/item/6zv402vr |
op_rights |
CC-BY |
_version_ |
1778533769154658304 |