Estimation of air-sea CO2 flux in Hudson Bay during the ice-free season using a combination of field data and satellite remote sensing products

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dc.contributor.advisorYackel, John
dc.contributor.advisorPapakyriakou, Tim
dc.contributor.authorElse, Brent Gordon Thomas
dc.date.accessioned2017-12-18T21:32:50Z
dc.date.available2017-12-18T21:32:50Z
dc.date.issued2007
dc.descriptionBibliography: p. 125-141en
dc.descriptionSome pages are in colour.en
dc.description.abstractThe lack of baseline estimates of air-sea CO₂ exchange in Arctic and sub-Arctic regions represents a major shortfall in our ability to understand how climate change may affect CO₂ fluxes at high latitude. The 2005 ArcticNet cruise of Hudson Bay provided a rare comprehensive oceanographic survey of one such region. Ship-based observations of sea­surface fugacity of CO₂ (fCO₂sw) were made at 56 locations between September 15 and October 26, and were found to range from 259µ atm in Hudson Strait to 425µ atm at the entrance to James Bay. Strong relationships between fCO₂sw and river discharge were identified, with coastal waters observed to be supersaturated in fCO₂sw with respect to the atmosphere (and thus a source of CO₂), while off-shore waters were undersaturated (thus a sink). High correlation of fCO₂sw with salinity, sea surface temperature (SST), and colored dissolved organic matter (CDOM) suggest that thermodynamic effects and possibly the oxidation of riverine carbon were driving supersaturation in the coastal zone. To expand the spatial and temporal domain of the study, a remote sensing approach was applied. Predictive algorithms for fCO₂sw were created from relationships with CDOM and SST; variables which can be measured from satellite remote sensing platforms. A SST­ fCO₂sw algorithm was used with monthly maps of SST obtained from the MODIS aqua sensor to extrapolate fCO₂sw in Hudson Bay for the 2005 ice-free season (August-October). Gas transfer velocities were estimated using twice-daily QuikSCAT wind retrievals, and by using a bulk aerodynamic approach the monthly flux of CO₂ in Hudson Bay was calculated. The results of these calculations revealed that Hudson Bay acts as a source of CO₂ during August and September (4.10 and 5.29 mmol m⁻² day⁻¹, respectively), but reverts to a sink of CO₂ in October as the water temperature cools (-5.83 mmol⁻² day⁻¹). By integrating over the spatial extent of Hudson Bay and the 92 day open-water season, a positive flux of 0.93 TgC was estimated. This result is in contrast to most Arctic or sub-Arctic continental shelf seas, where usually strong absorptions of CO₂ are observed. It is hypothesized that this difference is related to the strong influence of river discharge. Future studies are necessary to constrain fluxes in Hudson Bay over an annual cycle and to determine the oceanographic controls on CO₂ flux. However, this study is significant since it represents the first-ever examination of air-sea CO₂ exchange in Hudson Bay.en
dc.format.extentxvi, 141 leaves : ill. ; 30 cm.en
dc.identifier.citationElse, B. G. (2007). Estimation of air-sea CO2 flux in Hudson Bay during the ice-free season using a combination of field data and satellite remote sensing products (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/1685en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/1685
dc.identifier.urihttp://hdl.handle.net/1880/102686
dc.language.isoeng
dc.publisher.institutionUniversity of Calgaryen
dc.publisher.placeCalgaryen
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.titleEstimation of air-sea CO2 flux in Hudson Bay during the ice-free season using a combination of field data and satellite remote sensing products
dc.typemaster thesis
thesis.degree.disciplineGeography
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameMaster of Science (MSc)
ucalgary.item.requestcopytrue
ucalgary.thesis.accessionTheses Collection 58.002:Box 1712 520492229
ucalgary.thesis.notesUARCen
ucalgary.thesis.uarcreleaseyen
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