Quality control of oceanographic in situ data from Argo floats using climatological convex hulls
A new method of identifying anomalous oceanic temperature and salinity (T/S) data from Argo profiling floats is proposed. The proposed method uses World Ocean Database 2013 climatology to classify good against anomalous data by using convex hulls. An n-sided polygon (convex hull) with least area enc...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2017-01-01
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| Series: | MethodsX |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2215016117300560 |
| _version_ | 1819077587652050944 |
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| author | T.V.S. Udaya Bhaskar R. Venkat Shesu Timothy P. Boyer E. Pattabhi Rama Rao |
| author_facet | T.V.S. Udaya Bhaskar R. Venkat Shesu Timothy P. Boyer E. Pattabhi Rama Rao |
| author_sort | T.V.S. Udaya Bhaskar |
| collection | DOAJ |
| description | A new method of identifying anomalous oceanic temperature and salinity (T/S) data from Argo profiling floats is proposed. The proposed method uses World Ocean Database 2013 climatology to classify good against anomalous data by using convex hulls. An n-sided polygon (convex hull) with least area encompassing all the climatological points is constructed using Jarvis March algorithm. Subsequently Points In Polygon (PIP) principle implemented using ray casting algorithm is used to classify the T/S data as within or without acceptable bounds. It is observed that various types of anomalies associated with the oceanographic data viz., spikes, bias, sensor drifts etc can be identified using this method. Though demonstrated for Argo data it can be applied to any oceanographic data.
• The patterns of variation of the parameter (temperature or salinity) corresponding to a particular depth, along the longitude or latitude can be used to build convex hulls.
• This method can be effectively used for quality control by building Convex hulls for various observed depths corresponding to biogeochemical data which are sparsely observed.
• This method has the advantage of treating the bulk of oceanographic in situ data in a single iteration which filters out anomalous data. |
| first_indexed | 2024-12-21T18:59:34Z |
| format | Article |
| id | doaj.art-9b199d8c2a9a495dbb626d2c46ac6eb9 |
| institution | Directory Open Access Journal |
| issn | 2215-0161 |
| language | English |
| last_indexed | 2024-12-21T18:59:34Z |
| publishDate | 2017-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | MethodsX |
| spelling | doaj.art-9b199d8c2a9a495dbb626d2c46ac6eb92022-12-21T18:53:31ZengElsevierMethodsX2215-01612017-01-014C46947910.1016/j.mex.2017.11.007Quality control of oceanographic in situ data from Argo floats using climatological convex hullsT.V.S. Udaya Bhaskar0R. Venkat Shesu1Timothy P. Boyer2E. Pattabhi Rama Rao3Indian National Centre for Ocean Information Services (INCOIS), MoES, Hyderabad, IndiaIndian National Centre for Ocean Information Services (INCOIS), MoES, Hyderabad, IndiaNational Centers for Environmental Information (NCEI), Silver Spring, MD 20910-3282, USAIndian National Centre for Ocean Information Services (INCOIS), MoES, Hyderabad, IndiaA new method of identifying anomalous oceanic temperature and salinity (T/S) data from Argo profiling floats is proposed. The proposed method uses World Ocean Database 2013 climatology to classify good against anomalous data by using convex hulls. An n-sided polygon (convex hull) with least area encompassing all the climatological points is constructed using Jarvis March algorithm. Subsequently Points In Polygon (PIP) principle implemented using ray casting algorithm is used to classify the T/S data as within or without acceptable bounds. It is observed that various types of anomalies associated with the oceanographic data viz., spikes, bias, sensor drifts etc can be identified using this method. Though demonstrated for Argo data it can be applied to any oceanographic data. • The patterns of variation of the parameter (temperature or salinity) corresponding to a particular depth, along the longitude or latitude can be used to build convex hulls. • This method can be effectively used for quality control by building Convex hulls for various observed depths corresponding to biogeochemical data which are sparsely observed. • This method has the advantage of treating the bulk of oceanographic in situ data in a single iteration which filters out anomalous data.http://www.sciencedirect.com/science/article/pii/S2215016117300560Climatological convex hulls for outlier detection |
| spellingShingle | T.V.S. Udaya Bhaskar R. Venkat Shesu Timothy P. Boyer E. Pattabhi Rama Rao Quality control of oceanographic in situ data from Argo floats using climatological convex hulls MethodsX Climatological convex hulls for outlier detection |
| title | Quality control of oceanographic in situ data from Argo floats using climatological convex hulls |
| title_full | Quality control of oceanographic in situ data from Argo floats using climatological convex hulls |
| title_fullStr | Quality control of oceanographic in situ data from Argo floats using climatological convex hulls |
| title_full_unstemmed | Quality control of oceanographic in situ data from Argo floats using climatological convex hulls |
| title_short | Quality control of oceanographic in situ data from Argo floats using climatological convex hulls |
| title_sort | quality control of oceanographic in situ data from argo floats using climatological convex hulls |
| topic | Climatological convex hulls for outlier detection |
| url | http://www.sciencedirect.com/science/article/pii/S2215016117300560 |
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