Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation
This study examined fluxes across the ice-water interface utilizing the eddy correlation technique. Temperature eddy correlation systems were used to determine rates of ice melting and freezing, and O2 eddy correlation systems were used to examine O2 exchange rates driven by biological and physical...
Published in: | Biogeosciences |
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Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2012
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Online Access: | https://pure.au.dk/portal/da/publications/oxygen-exchange-and-ice-melt-measured-at-the-icewater-interface-by-eddy-correlation(1708cca3-2aea-47c5-a086-1e1d91dab50d).html https://doi.org/10.5194/bg-9-1957-2012 http://www.scopus.com/inward/record.url?eid=2-s2.0-84861805350&partnerID=40&md5=5ebed54db367442fef24d8430a104cfc |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/1708cca3-2aea-47c5-a086-1e1d91dab50d 2023-05-15T15:18:55+02:00 Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation Long, M.H. Koopmans, D. Berg, P. Rysgaard, Søren Glud, Ronnie Nøhr Soøgaard, D.H. 2012 https://pure.au.dk/portal/da/publications/oxygen-exchange-and-ice-melt-measured-at-the-icewater-interface-by-eddy-correlation(1708cca3-2aea-47c5-a086-1e1d91dab50d).html https://doi.org/10.5194/bg-9-1957-2012 http://www.scopus.com/inward/record.url?eid=2-s2.0-84861805350&partnerID=40&md5=5ebed54db367442fef24d8430a104cfc eng eng info:eu-repo/semantics/restrictedAccess Long , M H , Koopmans , D , Berg , P , Rysgaard , S , Glud , R N & Soøgaard , D H 2012 , ' Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation ' , Biogeosciences , vol. 9 , no. 6 , pp. 1957-1967 . https://doi.org/10.5194/bg-9-1957-2012 alga environmental conditions fjord freezing gas exchange ice mechanics irradiance melting meltwater microbial community net primary production oxygen photosynthesis respiration sea ice turbulent mixing Arctic Greenland algae article 2012 ftuniaarhuspubl https://doi.org/10.5194/bg-9-1957-2012 2020-07-18T21:23:45Z This study examined fluxes across the ice-water interface utilizing the eddy correlation technique. Temperature eddy correlation systems were used to determine rates of ice melting and freezing, and O2 eddy correlation systems were used to examine O2 exchange rates driven by biological and physical processes. The study was conducted below 0.7 m thick sea-ice in mid-March 2010 in a southwest Greenland fjord and revealed low rates of ice melt at a maximum of 0.80 mm dĝ̂'1. The O2 flux associated with release of O2 depleted melt water was less than 13 % of the average daily O2 respiration rate. Ice melt and insufficient vertical turbulent mixing due to low current velocities caused periodic stratification immediately below the ice. This prevented the determination of fluxes 61 % of the deployment time. These time intervals were identified by examining the velocity and the linearity and stability of the cumulative flux. The examination of unstratified conditions through vertical velocity and O2 spectra and their cospectra revealed characteristic fingerprints of well-developed turbulence. From the measured O2 fluxes a photosynthesis/irradiance curve was established by least-squares fitting. This relation showed that light limitation of net photosynthesis began at 4.2 1/4mol photons mĝ̂'2 sĝ̂'1, and that algal communities were well-adapted to low-light conditions as they were light saturated for 75 % of the day during this early spring period. However, the sea-ice associated microbial and algal community was net heterotrophic with a daily gross primary production of 0.69 mmol O2 mĝ̂'2 dĝ̂'1 and a respiration rate of ĝ̂'2.13 mmol O2 mĝ̂'2 dĝ̂'1 leading to a net ecosystem metabolism of ĝ̂'1.45 mmol O2 mĝ̂'2 dĝ̂'1. This application of the eddy correlation technique produced high temporal resolution O2 fluxes and ice melt rates that were measured without disturbing the in situ environmental conditions while integrating over an area of approximately 50 m2 which incorporated the highly variable activity and spatial distributions of sea-ice communities. © Author(s) 2012. Article in Journal/Newspaper Arctic Greenland Sea ice Aarhus University: Research Arctic Greenland Biogeosciences 9 6 1957 1967 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
alga environmental conditions fjord freezing gas exchange ice mechanics irradiance melting meltwater microbial community net primary production oxygen photosynthesis respiration sea ice turbulent mixing Arctic Greenland algae |
spellingShingle |
alga environmental conditions fjord freezing gas exchange ice mechanics irradiance melting meltwater microbial community net primary production oxygen photosynthesis respiration sea ice turbulent mixing Arctic Greenland algae Long, M.H. Koopmans, D. Berg, P. Rysgaard, Søren Glud, Ronnie Nøhr Soøgaard, D.H. Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation |
topic_facet |
alga environmental conditions fjord freezing gas exchange ice mechanics irradiance melting meltwater microbial community net primary production oxygen photosynthesis respiration sea ice turbulent mixing Arctic Greenland algae |
description |
This study examined fluxes across the ice-water interface utilizing the eddy correlation technique. Temperature eddy correlation systems were used to determine rates of ice melting and freezing, and O2 eddy correlation systems were used to examine O2 exchange rates driven by biological and physical processes. The study was conducted below 0.7 m thick sea-ice in mid-March 2010 in a southwest Greenland fjord and revealed low rates of ice melt at a maximum of 0.80 mm dĝ̂'1. The O2 flux associated with release of O2 depleted melt water was less than 13 % of the average daily O2 respiration rate. Ice melt and insufficient vertical turbulent mixing due to low current velocities caused periodic stratification immediately below the ice. This prevented the determination of fluxes 61 % of the deployment time. These time intervals were identified by examining the velocity and the linearity and stability of the cumulative flux. The examination of unstratified conditions through vertical velocity and O2 spectra and their cospectra revealed characteristic fingerprints of well-developed turbulence. From the measured O2 fluxes a photosynthesis/irradiance curve was established by least-squares fitting. This relation showed that light limitation of net photosynthesis began at 4.2 1/4mol photons mĝ̂'2 sĝ̂'1, and that algal communities were well-adapted to low-light conditions as they were light saturated for 75 % of the day during this early spring period. However, the sea-ice associated microbial and algal community was net heterotrophic with a daily gross primary production of 0.69 mmol O2 mĝ̂'2 dĝ̂'1 and a respiration rate of ĝ̂'2.13 mmol O2 mĝ̂'2 dĝ̂'1 leading to a net ecosystem metabolism of ĝ̂'1.45 mmol O2 mĝ̂'2 dĝ̂'1. This application of the eddy correlation technique produced high temporal resolution O2 fluxes and ice melt rates that were measured without disturbing the in situ environmental conditions while integrating over an area of approximately 50 m2 which incorporated the highly variable activity and spatial distributions of sea-ice communities. © Author(s) 2012. |
format |
Article in Journal/Newspaper |
author |
Long, M.H. Koopmans, D. Berg, P. Rysgaard, Søren Glud, Ronnie Nøhr Soøgaard, D.H. |
author_facet |
Long, M.H. Koopmans, D. Berg, P. Rysgaard, Søren Glud, Ronnie Nøhr Soøgaard, D.H. |
author_sort |
Long, M.H. |
title |
Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation |
title_short |
Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation |
title_full |
Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation |
title_fullStr |
Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation |
title_full_unstemmed |
Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation |
title_sort |
oxygen exchange and ice melt measured at the ice-water interface by eddy correlation |
publishDate |
2012 |
url |
https://pure.au.dk/portal/da/publications/oxygen-exchange-and-ice-melt-measured-at-the-icewater-interface-by-eddy-correlation(1708cca3-2aea-47c5-a086-1e1d91dab50d).html https://doi.org/10.5194/bg-9-1957-2012 http://www.scopus.com/inward/record.url?eid=2-s2.0-84861805350&partnerID=40&md5=5ebed54db367442fef24d8430a104cfc |
geographic |
Arctic Greenland |
geographic_facet |
Arctic Greenland |
genre |
Arctic Greenland Sea ice |
genre_facet |
Arctic Greenland Sea ice |
op_source |
Long , M H , Koopmans , D , Berg , P , Rysgaard , S , Glud , R N & Soøgaard , D H 2012 , ' Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation ' , Biogeosciences , vol. 9 , no. 6 , pp. 1957-1967 . https://doi.org/10.5194/bg-9-1957-2012 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.5194/bg-9-1957-2012 |
container_title |
Biogeosciences |
container_volume |
9 |
container_issue |
6 |
container_start_page |
1957 |
op_container_end_page |
1967 |
_version_ |
1766349088442286080 |