Climate change and the effect of darker coastal water on NCW euphotic zone properties - A theoretical study
The Norwegian Coastal Water (NCW) derives from an extensive outflow of freshwater from the Baltic Sea and river runoff from the Norwegian coast, making the water less saline than the North Atlantic Water (NAW). Freshwater components contain relatively large amounts of dissolved organic substances th...
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2016
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ftunivbergen:oai:bora.uib.no:1956/15376 2023-05-15T17:36:56+02:00 Climate change and the effect of darker coastal water on NCW euphotic zone properties - A theoretical study Ihler, Vilde Steinsdotter 2016-11-21 8711205 bytes application/pdf https://hdl.handle.net/1956/15376 eng eng The University of Bergen https://hdl.handle.net/1956/15376 Copyright the Author. All rights reserved Kystfarvann Løst naturlig organisk materiale Planteplankton Norge Eufotisk sone Vannformørkning https://data.ub.uio.no/realfagstermer/c030753 https://data.ub.uio.no/realfagstermer/c032075 https://data.ub.uio.no/realfagstermer/c006601 https://data.ub.uio.no/realfagstermer/c010560 https://data.ub.uio.no/realfagstermer/c032074 https://data.ub.uio.no/realfagstermer/c008279 751999 Master thesis 2016 ftunivbergen 2023-03-14T17:41:24Z The Norwegian Coastal Water (NCW) derives from an extensive outflow of freshwater from the Baltic Sea and river runoff from the Norwegian coast, making the water less saline than the North Atlantic Water (NAW). Freshwater components contain relatively large amounts of dissolved organic substances that absorb light, which have been suggested to make the NCW darker than the NAW. Such substances may have both marine and terrestrial origin and are often referred to as chromophoric dissolved organic matter (CDOM). An increased CDOM concentration is predicted in the freshwater component of the NCW in the future, with possible implications on the biological ecosystem. The water column model of nutrient and phytoplankton of Huisman et al. (2006) was applied to analyse how NCW euphotic zone properties would respond to changes in CDOM attenuation in a past, present and future scenario. This model was originally parameterized for subtropical conditions, i.e. for oligotrophic waters. I investigated the extent to which the model could reproduce the vertical distribution of nutrients and phytoplankton under NCW conditions, i.e. more eutrophic waters, using data from previously published studies from three fjord locations along southern Norway. Further, published studies on Secchi depth observation and predicted future changes in terrestrial organic matter were used as a proxy for CDOM supply to the freshwater draining to the NCW. IMRs fixed hydrographic stations have been used as a proxy for changes in salinity and stratification. My results suggest that the NCW euphotic zone properties are susceptible to variation in CDOM attenuation. The estimated changes in the NCW euphotic zone properties are also suggested to be greater in the future than those estimated for the past. From two coastal stations, Lista and Sognesjøen, it was suggested a 5 meter reduction in the euphotic depth from the present to a future scenario. Elevated CDOM attenuation in the future is also expected to show eutrophication like symptoms. However, the ... Master Thesis North Atlantic University of Bergen: Bergen Open Research Archive (BORA-UiB) Norway |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
Kystfarvann Løst naturlig organisk materiale Planteplankton Norge Eufotisk sone Vannformørkning https://data.ub.uio.no/realfagstermer/c030753 https://data.ub.uio.no/realfagstermer/c032075 https://data.ub.uio.no/realfagstermer/c006601 https://data.ub.uio.no/realfagstermer/c010560 https://data.ub.uio.no/realfagstermer/c032074 https://data.ub.uio.no/realfagstermer/c008279 751999 |
spellingShingle |
Kystfarvann Løst naturlig organisk materiale Planteplankton Norge Eufotisk sone Vannformørkning https://data.ub.uio.no/realfagstermer/c030753 https://data.ub.uio.no/realfagstermer/c032075 https://data.ub.uio.no/realfagstermer/c006601 https://data.ub.uio.no/realfagstermer/c010560 https://data.ub.uio.no/realfagstermer/c032074 https://data.ub.uio.no/realfagstermer/c008279 751999 Ihler, Vilde Steinsdotter Climate change and the effect of darker coastal water on NCW euphotic zone properties - A theoretical study |
topic_facet |
Kystfarvann Løst naturlig organisk materiale Planteplankton Norge Eufotisk sone Vannformørkning https://data.ub.uio.no/realfagstermer/c030753 https://data.ub.uio.no/realfagstermer/c032075 https://data.ub.uio.no/realfagstermer/c006601 https://data.ub.uio.no/realfagstermer/c010560 https://data.ub.uio.no/realfagstermer/c032074 https://data.ub.uio.no/realfagstermer/c008279 751999 |
description |
The Norwegian Coastal Water (NCW) derives from an extensive outflow of freshwater from the Baltic Sea and river runoff from the Norwegian coast, making the water less saline than the North Atlantic Water (NAW). Freshwater components contain relatively large amounts of dissolved organic substances that absorb light, which have been suggested to make the NCW darker than the NAW. Such substances may have both marine and terrestrial origin and are often referred to as chromophoric dissolved organic matter (CDOM). An increased CDOM concentration is predicted in the freshwater component of the NCW in the future, with possible implications on the biological ecosystem. The water column model of nutrient and phytoplankton of Huisman et al. (2006) was applied to analyse how NCW euphotic zone properties would respond to changes in CDOM attenuation in a past, present and future scenario. This model was originally parameterized for subtropical conditions, i.e. for oligotrophic waters. I investigated the extent to which the model could reproduce the vertical distribution of nutrients and phytoplankton under NCW conditions, i.e. more eutrophic waters, using data from previously published studies from three fjord locations along southern Norway. Further, published studies on Secchi depth observation and predicted future changes in terrestrial organic matter were used as a proxy for CDOM supply to the freshwater draining to the NCW. IMRs fixed hydrographic stations have been used as a proxy for changes in salinity and stratification. My results suggest that the NCW euphotic zone properties are susceptible to variation in CDOM attenuation. The estimated changes in the NCW euphotic zone properties are also suggested to be greater in the future than those estimated for the past. From two coastal stations, Lista and Sognesjøen, it was suggested a 5 meter reduction in the euphotic depth from the present to a future scenario. Elevated CDOM attenuation in the future is also expected to show eutrophication like symptoms. However, the ... |
format |
Master Thesis |
author |
Ihler, Vilde Steinsdotter |
author_facet |
Ihler, Vilde Steinsdotter |
author_sort |
Ihler, Vilde Steinsdotter |
title |
Climate change and the effect of darker coastal water on NCW euphotic zone properties - A theoretical study |
title_short |
Climate change and the effect of darker coastal water on NCW euphotic zone properties - A theoretical study |
title_full |
Climate change and the effect of darker coastal water on NCW euphotic zone properties - A theoretical study |
title_fullStr |
Climate change and the effect of darker coastal water on NCW euphotic zone properties - A theoretical study |
title_full_unstemmed |
Climate change and the effect of darker coastal water on NCW euphotic zone properties - A theoretical study |
title_sort |
climate change and the effect of darker coastal water on ncw euphotic zone properties - a theoretical study |
publisher |
The University of Bergen |
publishDate |
2016 |
url |
https://hdl.handle.net/1956/15376 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://hdl.handle.net/1956/15376 |
op_rights |
Copyright the Author. All rights reserved |
_version_ |
1766136582843138048 |