Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf
Alkalinity (Alk) and (Dissolved Inorganic Carbon) DIC were measured on high resolution seawater samples, collected on November 2018 and May 2019 at seven stations in the Exclusive Economic Zone (EEZ) of Qatar. Calculated surface PCO2 averaged 472 matm in 2018 and 447 matm in 2019. Thus: the Arabian...
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ftqataruniv:oai:qspace.qu.edu.qa:10576/16565 2023-05-15T17:50:21+02:00 Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf Al-Thani, Jassem A. Izumi, Connor Yigiterhan, Oguz Al-Ansari, Ebrahim Mohd A S Vethamony, Ponnumony Sorino, Caesar Flonasca Anderson, Dan Murray, James W. application/pdf http://hdl.handle.net/10576/16565 https://doi.org/10.29117/quarfe.2020.0030 en eng Qatar University Press AlThani J.A., Izumi C., Yigiterhan O., AlAnsari E.M.A.S., Vethamony P., Sorino C.F., Anderson D., Murray J.W., "Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf", Qatar University Annual Research Forum and Exhibition (QUARFE 2020), Doha, 2020, https://doi.org/10.29117/quarfe.2020.0030 https://doi.org/10.29117/quarfe.2020.0030 http://hdl.handle.net/10576/16565 Ocean Acidification Marine Geochemistry Climate Change Marine Environment Arabian Gulf Poster ftqataruniv https://doi.org/10.29117/quarfe.2020.0030 2022-07-13T15:12:09Z Alkalinity (Alk) and (Dissolved Inorganic Carbon) DIC were measured on high resolution seawater samples, collected on November 2018 and May 2019 at seven stations in the Exclusive Economic Zone (EEZ) of Qatar. Calculated surface PCO2 averaged 472 matm in 2018 and 447 matm in 2019. Thus: the Arabian Gulf is degassing CO2 at present and will not take up atmospheric CO2 until 2042. Ocean acidification is not yet an issue in the EEZ of Qatar. The elevated PCO2 values are due to CaCO3 formation. Normalized NAlk and NDIC were calculated to remove the impact of increasing salinity. NAlk and NDIC decrease corresponding to a CaCO3/OrgC removal ratio of 2/1. We calculated the nitrate corrected and salinity normalized tracer, Alk*. Values of Alk* were negative, and the change in Alk* relative to Hormuz (DAlk*) indicated that there has been an average decrease of Alk* of -130 mmol kg-1. This decrease is due to CaCO3 formation but previous studies found no evidence for coccolithophorids. One obvious possibility is that Alk removal is due to CaCO3 formation in coral reefs. However, recent study of the composition of particulate matter found that the average particulate Ca concentration was 3.6%, and was easily acid soluble (Yigiterhan et al, 2018). These results suggest that a significant amount of particulate CaCO3 is present in the water column. One hypothesis is that the particulate Ca comes from carbonate rich atmospheric dust. Using Al as a tracer for dust and the average Ca/Al ratio in Qatari dust can only explain about 3% of the particulate Ca. An alternative hypothesis is that particulate CaCO3 may form in the water column due to abiological CaCO3 formation, as proposed recently for the Red Sea (Wurgaft et al., 2016). Precipitation of CaCO3 may be induced by the large inputs of nucleation sites in the form of atmospheric dust. Still Image Ocean acidification Qatar University: QU Institutional Repository University of the Future: Re-Imagining Research and Higher Education 57 |
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Open Polar |
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Qatar University: QU Institutional Repository |
op_collection_id |
ftqataruniv |
language |
English |
topic |
Ocean Acidification Marine Geochemistry Climate Change Marine Environment Arabian Gulf |
spellingShingle |
Ocean Acidification Marine Geochemistry Climate Change Marine Environment Arabian Gulf Al-Thani, Jassem A. Izumi, Connor Yigiterhan, Oguz Al-Ansari, Ebrahim Mohd A S Vethamony, Ponnumony Sorino, Caesar Flonasca Anderson, Dan Murray, James W. Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf |
topic_facet |
Ocean Acidification Marine Geochemistry Climate Change Marine Environment Arabian Gulf |
description |
Alkalinity (Alk) and (Dissolved Inorganic Carbon) DIC were measured on high resolution seawater samples, collected on November 2018 and May 2019 at seven stations in the Exclusive Economic Zone (EEZ) of Qatar. Calculated surface PCO2 averaged 472 matm in 2018 and 447 matm in 2019. Thus: the Arabian Gulf is degassing CO2 at present and will not take up atmospheric CO2 until 2042. Ocean acidification is not yet an issue in the EEZ of Qatar. The elevated PCO2 values are due to CaCO3 formation. Normalized NAlk and NDIC were calculated to remove the impact of increasing salinity. NAlk and NDIC decrease corresponding to a CaCO3/OrgC removal ratio of 2/1. We calculated the nitrate corrected and salinity normalized tracer, Alk*. Values of Alk* were negative, and the change in Alk* relative to Hormuz (DAlk*) indicated that there has been an average decrease of Alk* of -130 mmol kg-1. This decrease is due to CaCO3 formation but previous studies found no evidence for coccolithophorids. One obvious possibility is that Alk removal is due to CaCO3 formation in coral reefs. However, recent study of the composition of particulate matter found that the average particulate Ca concentration was 3.6%, and was easily acid soluble (Yigiterhan et al, 2018). These results suggest that a significant amount of particulate CaCO3 is present in the water column. One hypothesis is that the particulate Ca comes from carbonate rich atmospheric dust. Using Al as a tracer for dust and the average Ca/Al ratio in Qatari dust can only explain about 3% of the particulate Ca. An alternative hypothesis is that particulate CaCO3 may form in the water column due to abiological CaCO3 formation, as proposed recently for the Red Sea (Wurgaft et al., 2016). Precipitation of CaCO3 may be induced by the large inputs of nucleation sites in the form of atmospheric dust. |
format |
Still Image |
author |
Al-Thani, Jassem A. Izumi, Connor Yigiterhan, Oguz Al-Ansari, Ebrahim Mohd A S Vethamony, Ponnumony Sorino, Caesar Flonasca Anderson, Dan Murray, James W. |
author_facet |
Al-Thani, Jassem A. Izumi, Connor Yigiterhan, Oguz Al-Ansari, Ebrahim Mohd A S Vethamony, Ponnumony Sorino, Caesar Flonasca Anderson, Dan Murray, James W. |
author_sort |
Al-Thani, Jassem A. |
title |
Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf |
title_short |
Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf |
title_full |
Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf |
title_fullStr |
Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf |
title_full_unstemmed |
Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf |
title_sort |
ocean acidification and carbonate system geochemistry in the arabian gulf |
publisher |
Qatar University Press |
url |
http://hdl.handle.net/10576/16565 https://doi.org/10.29117/quarfe.2020.0030 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
AlThani J.A., Izumi C., Yigiterhan O., AlAnsari E.M.A.S., Vethamony P., Sorino C.F., Anderson D., Murray J.W., "Ocean Acidification and Carbonate System Geochemistry in the Arabian Gulf", Qatar University Annual Research Forum and Exhibition (QUARFE 2020), Doha, 2020, https://doi.org/10.29117/quarfe.2020.0030 https://doi.org/10.29117/quarfe.2020.0030 http://hdl.handle.net/10576/16565 |
op_doi |
https://doi.org/10.29117/quarfe.2020.0030 |
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University of the Future: Re-Imagining Research and Higher Education |
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57 |
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