Automated identification of local contamination in remote atmospheric composition time series
Atmospheric observations in remote locations offer a possibility of exploring trace gas and particle concentrations in pristine environments. However, data from remote areas are often contaminated by pollution from local sources. Detecting this contamination is thus a central and frequently encounte...
Published in: | Atmospheric Measurement Techniques |
---|---|
Main Authors: | , , , , , , , , , , , , , , |
Format: | Text |
Language: | English |
Published: |
2022
|
Subjects: | |
Online Access: | https://doi.org/10.5194/amt-15-4195-2022 https://amt.copernicus.org/articles/15/4195/2022/ |
id |
ftcopernicus:oai:publications.copernicus.org:amt100328 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:amt100328 2023-05-15T15:02:17+02:00 Automated identification of local contamination in remote atmospheric composition time series Beck, Ivo Angot, Hélène Baccarini, Andrea Dada, Lubna Quéléver, Lauriane Jokinen, Tuija Laurila, Tiia Lampimäki, Markus Bukowiecki, Nicolas Boyer, Matthew Gong, Xianda Gysel-Beer, Martin Petäjä, Tuukka Wang, Jian Schmale, Julia 2022-07-20 application/pdf https://doi.org/10.5194/amt-15-4195-2022 https://amt.copernicus.org/articles/15/4195/2022/ eng eng doi:10.5194/amt-15-4195-2022 https://amt.copernicus.org/articles/15/4195/2022/ eISSN: 1867-8548 Text 2022 ftcopernicus https://doi.org/10.5194/amt-15-4195-2022 2022-07-25T16:22:41Z Atmospheric observations in remote locations offer a possibility of exploring trace gas and particle concentrations in pristine environments. However, data from remote areas are often contaminated by pollution from local sources. Detecting this contamination is thus a central and frequently encountered issue. Consequently, many different methods exist today to identify local contamination in atmospheric composition measurement time series, but no single method has been widely accepted. In this study, we present a new method to identify primary pollution in remote atmospheric datasets, e.g., from ship campaigns or stations with a low background signal compared to the contaminated signal. The pollution detection algorithm (PDA) identifies and flags periods of polluted data in five steps. The first and most important step identifies polluted periods based on the derivative (time derivative) of a concentration over time. If this derivative exceeds a given threshold, data are flagged as polluted. Further pollution identification steps are a simple concentration threshold filter, a neighboring points filter (optional), a median, and a sparse data filter (optional). The PDA only relies on the target dataset itself and is independent of ancillary datasets such as meteorological variables. All parameters of each step are adjustable so that the PDA can be “tuned” to be more or less stringent (e.g., flag more or fewer data points as contaminated). The PDA was developed and tested with a particle number concentration dataset collected during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition in the central Arctic. Using strict settings, we identified 62 % of the data as influenced by local contamination. Using a second independent particle number concentration dataset also collected during MOSAiC, we evaluated the performance of the PDA against the same dataset cleaned by visual inspection. The two methods agreed in 94 % of the cases. Additionally, the PDA was successfully applied ... Text Arctic Copernicus Publications: E-Journals Arctic Atmospheric Measurement Techniques 15 14 4195 4224 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Atmospheric observations in remote locations offer a possibility of exploring trace gas and particle concentrations in pristine environments. However, data from remote areas are often contaminated by pollution from local sources. Detecting this contamination is thus a central and frequently encountered issue. Consequently, many different methods exist today to identify local contamination in atmospheric composition measurement time series, but no single method has been widely accepted. In this study, we present a new method to identify primary pollution in remote atmospheric datasets, e.g., from ship campaigns or stations with a low background signal compared to the contaminated signal. The pollution detection algorithm (PDA) identifies and flags periods of polluted data in five steps. The first and most important step identifies polluted periods based on the derivative (time derivative) of a concentration over time. If this derivative exceeds a given threshold, data are flagged as polluted. Further pollution identification steps are a simple concentration threshold filter, a neighboring points filter (optional), a median, and a sparse data filter (optional). The PDA only relies on the target dataset itself and is independent of ancillary datasets such as meteorological variables. All parameters of each step are adjustable so that the PDA can be “tuned” to be more or less stringent (e.g., flag more or fewer data points as contaminated). The PDA was developed and tested with a particle number concentration dataset collected during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition in the central Arctic. Using strict settings, we identified 62 % of the data as influenced by local contamination. Using a second independent particle number concentration dataset also collected during MOSAiC, we evaluated the performance of the PDA against the same dataset cleaned by visual inspection. The two methods agreed in 94 % of the cases. Additionally, the PDA was successfully applied ... |
format |
Text |
author |
Beck, Ivo Angot, Hélène Baccarini, Andrea Dada, Lubna Quéléver, Lauriane Jokinen, Tuija Laurila, Tiia Lampimäki, Markus Bukowiecki, Nicolas Boyer, Matthew Gong, Xianda Gysel-Beer, Martin Petäjä, Tuukka Wang, Jian Schmale, Julia |
spellingShingle |
Beck, Ivo Angot, Hélène Baccarini, Andrea Dada, Lubna Quéléver, Lauriane Jokinen, Tuija Laurila, Tiia Lampimäki, Markus Bukowiecki, Nicolas Boyer, Matthew Gong, Xianda Gysel-Beer, Martin Petäjä, Tuukka Wang, Jian Schmale, Julia Automated identification of local contamination in remote atmospheric composition time series |
author_facet |
Beck, Ivo Angot, Hélène Baccarini, Andrea Dada, Lubna Quéléver, Lauriane Jokinen, Tuija Laurila, Tiia Lampimäki, Markus Bukowiecki, Nicolas Boyer, Matthew Gong, Xianda Gysel-Beer, Martin Petäjä, Tuukka Wang, Jian Schmale, Julia |
author_sort |
Beck, Ivo |
title |
Automated identification of local contamination in remote atmospheric composition time series |
title_short |
Automated identification of local contamination in remote atmospheric composition time series |
title_full |
Automated identification of local contamination in remote atmospheric composition time series |
title_fullStr |
Automated identification of local contamination in remote atmospheric composition time series |
title_full_unstemmed |
Automated identification of local contamination in remote atmospheric composition time series |
title_sort |
automated identification of local contamination in remote atmospheric composition time series |
publishDate |
2022 |
url |
https://doi.org/10.5194/amt-15-4195-2022 https://amt.copernicus.org/articles/15/4195/2022/ |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
eISSN: 1867-8548 |
op_relation |
doi:10.5194/amt-15-4195-2022 https://amt.copernicus.org/articles/15/4195/2022/ |
op_doi |
https://doi.org/10.5194/amt-15-4195-2022 |
container_title |
Atmospheric Measurement Techniques |
container_volume |
15 |
container_issue |
14 |
container_start_page |
4195 |
op_container_end_page |
4224 |
_version_ |
1766334248952791040 |