Modelling coupled physical-biogeochemical processes in ice-covered oceans
The last decades have seen a large effort of the scientific community to study and understand the physics of sea ice. We currently have a wide - even though still not exhaustive - knowledge of the sea ice dynamics and thermodynamics and of their temporal and spatial variability. Sea ice biogeochemis...
Main Author: | |
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Other Authors: | , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
Published: |
Alma Mater Studiorum - Università di Bologna
2009
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Subjects: | |
Online Access: | http://amsdottorato.unibo.it/1996/ http://amsdottorato.unibo.it/1996/1/letizia_tedesco_phd_thesis.pdf |
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ftunivbologntesi:oai:amsdottorato.cib.unibo.it:1996 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Università di Bologna: AMS Tesi di Dottorato (Alm@DL) |
op_collection_id |
ftunivbologntesi |
language |
English |
topic |
GEO/12 Oceanografia e fisica dell'atmosfera |
spellingShingle |
GEO/12 Oceanografia e fisica dell'atmosfera Tedesco, Letizia <1978> Modelling coupled physical-biogeochemical processes in ice-covered oceans |
topic_facet |
GEO/12 Oceanografia e fisica dell'atmosfera |
description |
The last decades have seen a large effort of the scientific community to study and understand the physics of sea ice. We currently have a wide - even though still not exhaustive - knowledge of the sea ice dynamics and thermodynamics and of their temporal and spatial variability. Sea ice biogeochemistry is instead largely unknown. Sea ice algae production may account for up to 25% of overall primary production in ice-covered waters of the Southern Ocean. However, the influence of physical factors, such as the location of ice formation, the role of snow cover and light availability on sea ice primary production is poorly understood. There are only sparse localized observations and little knowledge of the functioning of sea ice biogeochemistry at larger scales. Modelling becomes then an auxiliary tool to help qualifying and quantifying the role of sea ice biogeochemistry in the ocean dynamics. In this thesis, a novel approach is used for the modelling and coupling of sea ice biogeochemistry - and in particular its primary production - to sea ice physics. Previous attempts were based on the coupling of rather complex sea ice physical models to empirical or relatively simple biological or biogeochemical models. The focus is moved here to a more biologically-oriented point of view. A simple, however comprehensive, physical model of the sea ice thermodynamics (ESIM) was developed and coupled to a novel sea ice implementation (BFM-SI) of the Biogeochemical Flux Model (BFM). The BFM is a comprehensive model, largely used and validated in the open ocean environment and in regional seas. The physical model has been developed having in mind the biogeochemical properties of sea ice and the physical inputs required to model sea ice biogeochemistry. The central concept of the coupling is the modelling of the Biologically-Active-Layer (BAL), which is the time-varying fraction of sea ice that is continuously connected to the ocean via brines pockets and channels and it acts as rich habitat for many microorganisms. The physical model provides the key physical properties of the BAL (e.g., brines volume, temperature and salinity), and the BFM-SI simulates the physiological and ecological response of the biological community to the physical enviroment. The new biogeochemical model is also coupled to the pelagic BFM through the exchange of organic and inorganic matter at the boundaries between the two systems . This is done by computing the entrapment of matter and gases when sea ice grows and release to the ocean when sea ice melts to ensure mass conservation. The model was tested in different ice-covered regions of the world ocean to test the generality of the parameterizations. The focus was particularly on the regions of landfast ice, where primary production is generally large. The implementation of the BFM in sea ice and the coupling structure in General Circulation Models will add a new component to the latters (and in general to Earth System Models), which will be able to provide adequate estimate of the role and importance of sea ice biogeochemistry in the global carbon cycle. |
author2 |
Pinardi, Nadia Vichi, Marcello |
format |
Doctoral or Postdoctoral Thesis |
author |
Tedesco, Letizia <1978> |
author_facet |
Tedesco, Letizia <1978> |
author_sort |
Tedesco, Letizia <1978> |
title |
Modelling coupled physical-biogeochemical processes in ice-covered oceans |
title_short |
Modelling coupled physical-biogeochemical processes in ice-covered oceans |
title_full |
Modelling coupled physical-biogeochemical processes in ice-covered oceans |
title_fullStr |
Modelling coupled physical-biogeochemical processes in ice-covered oceans |
title_full_unstemmed |
Modelling coupled physical-biogeochemical processes in ice-covered oceans |
title_sort |
modelling coupled physical-biogeochemical processes in ice-covered oceans |
publisher |
Alma Mater Studiorum - Università di Bologna |
publishDate |
2009 |
url |
http://amsdottorato.unibo.it/1996/ http://amsdottorato.unibo.it/1996/1/letizia_tedesco_phd_thesis.pdf |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
ice algae Sea ice Southern Ocean ice covered waters |
genre_facet |
ice algae Sea ice Southern Ocean ice covered waters |
op_relation |
http://amsdottorato.unibo.it/1996/1/letizia_tedesco_phd_thesis.pdf urn:nbn:it:unibo-1566 Tedesco, Letizia (2009) Modelling coupled physical-biogeochemical processes in ice-covered oceans, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Scienze ambientali: tutela e gestione delle risorse naturali <http://amsdottorato.unibo.it/view/dottorati/DOT295/>, 21 Ciclo. |
op_rights |
info:eu-repo/semantics/restrictedAccess |
_version_ |
1766026920683634688 |
spelling |
ftunivbologntesi:oai:amsdottorato.cib.unibo.it:1996 2023-05-15T16:36:35+02:00 Modelling coupled physical-biogeochemical processes in ice-covered oceans Tedesco, Letizia <1978> Pinardi, Nadia Vichi, Marcello 2009-06-19 application/pdf http://amsdottorato.unibo.it/1996/ http://amsdottorato.unibo.it/1996/1/letizia_tedesco_phd_thesis.pdf en eng Alma Mater Studiorum - Università di Bologna http://amsdottorato.unibo.it/1996/1/letizia_tedesco_phd_thesis.pdf urn:nbn:it:unibo-1566 Tedesco, Letizia (2009) Modelling coupled physical-biogeochemical processes in ice-covered oceans, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Scienze ambientali: tutela e gestione delle risorse naturali <http://amsdottorato.unibo.it/view/dottorati/DOT295/>, 21 Ciclo. info:eu-repo/semantics/restrictedAccess GEO/12 Oceanografia e fisica dell'atmosfera Doctoral Thesis PeerReviewed 2009 ftunivbologntesi 2021-06-03T13:37:25Z The last decades have seen a large effort of the scientific community to study and understand the physics of sea ice. We currently have a wide - even though still not exhaustive - knowledge of the sea ice dynamics and thermodynamics and of their temporal and spatial variability. Sea ice biogeochemistry is instead largely unknown. Sea ice algae production may account for up to 25% of overall primary production in ice-covered waters of the Southern Ocean. However, the influence of physical factors, such as the location of ice formation, the role of snow cover and light availability on sea ice primary production is poorly understood. There are only sparse localized observations and little knowledge of the functioning of sea ice biogeochemistry at larger scales. Modelling becomes then an auxiliary tool to help qualifying and quantifying the role of sea ice biogeochemistry in the ocean dynamics. In this thesis, a novel approach is used for the modelling and coupling of sea ice biogeochemistry - and in particular its primary production - to sea ice physics. Previous attempts were based on the coupling of rather complex sea ice physical models to empirical or relatively simple biological or biogeochemical models. The focus is moved here to a more biologically-oriented point of view. A simple, however comprehensive, physical model of the sea ice thermodynamics (ESIM) was developed and coupled to a novel sea ice implementation (BFM-SI) of the Biogeochemical Flux Model (BFM). The BFM is a comprehensive model, largely used and validated in the open ocean environment and in regional seas. The physical model has been developed having in mind the biogeochemical properties of sea ice and the physical inputs required to model sea ice biogeochemistry. The central concept of the coupling is the modelling of the Biologically-Active-Layer (BAL), which is the time-varying fraction of sea ice that is continuously connected to the ocean via brines pockets and channels and it acts as rich habitat for many microorganisms. The physical model provides the key physical properties of the BAL (e.g., brines volume, temperature and salinity), and the BFM-SI simulates the physiological and ecological response of the biological community to the physical enviroment. The new biogeochemical model is also coupled to the pelagic BFM through the exchange of organic and inorganic matter at the boundaries between the two systems . This is done by computing the entrapment of matter and gases when sea ice grows and release to the ocean when sea ice melts to ensure mass conservation. The model was tested in different ice-covered regions of the world ocean to test the generality of the parameterizations. The focus was particularly on the regions of landfast ice, where primary production is generally large. The implementation of the BFM in sea ice and the coupling structure in General Circulation Models will add a new component to the latters (and in general to Earth System Models), which will be able to provide adequate estimate of the role and importance of sea ice biogeochemistry in the global carbon cycle. Doctoral or Postdoctoral Thesis ice algae Sea ice Southern Ocean ice covered waters Università di Bologna: AMS Tesi di Dottorato (Alm@DL) Southern Ocean |