Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 34 for “"sea ice extent"”.
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Antarctic sea-ice extent, Southern hemisphere circulation and South African rainfall
… model (OCM) to a reduction in Antarctic sea-ice extent during summer and winter, with emphasis on non-polar and southern African climates. Following an evaluation of the OCM, the control and perturbation simulations are analysed. The controls are forced by prescribed, observed sea surface …
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The Combined Role of ENSO-driven Sea Surface Temperature Variation and Arctic Sea Ice Extent in Defining Climate Conditions in the Southwestern United States
Previous research indicates that future reductions in Arctic sea ice cover (SIC) could alter storm tracks and precipitation patterns in western North America and negatively impact water resources in the American southwest. Other research suggests that multiple periods of increased precipitation …
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Assessment of early 20th Century climate model simulations of Antarctic Sea ice using historical commercial humpback whale catch data
… try understand its oceanographic features. The seasonal sea ice cover represents one major feature of this system. This study proposes to use other sources of data for the early 20th century that will help closing the gap prior to satellite observations. Humpback whales migrate poleward during …
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Arctic synoptic activity associated with sea ice variability using self-organizing maps
Relationships between synoptic activity and sea ice variability in the Arctic are studied using self-organizing maps (SOMs) to categorize observed weather patterns over the 1979-2010 period. The European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-interim, or ERAI) provides …
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On the use of multivariate statistics to validate global climate models
The goal of the present research was to investigate the low frequency modes of variability in the observed atmosphere and compare those to the counterpart modes in a Global Climate Model (GCM). As a means to accomplish this, a multivariate statistical technique introduced for the first time to the …
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Nitrogen uptake and phytoplankton productivity in the changing Barents Sea
… decades, with a significant reduction<br/>in sea ice extent and duration as a result. These sea ice changes and the resultant<br/>changes in ocean mixing are affecting nutrient supply, uptake and cycling and will<br/>have large-scale consequences for the distribution and magnitude of primary …
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Inferring ocean circulation during the Last Glacial Maximum and last deglaciation using data and models
… ~ 20,000 years ago) air temperatures warmed, sea level rose roughly 130 meters, and atmospheric concentrations of carbon dioxide increased. This thesis combines global models and paleoceanographic observations to constrain the ocean’s role in storing and transporting heat, salt, and other …
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Antarctic sea ice trends and its response to the Southern annular mode
Sea ice covers vast regions of the Southern Ocean and impacts on the climate as well as the plant and animal life of the region. The variability of sea ice in the Southern Ocean affects the entire food web of the region, from phytoplankton to Antarctic krill through to the apex predators such as …
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Inferring ocean circulation during the last glacial maximum and last deglaciation using data and models
… ~ 20,000 years ago) air temperatures warmed, sea level rose roughly 130 meters, and atmospheric concentrations of carbon dioxide increased. This thesis combines global models and paleoceanographic observations to constrain the ocean's role in storing and transporting heat, salt, and other …
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Multisensor Microwave Remote Sensing in the Cryosphere
… has proven to be a useful tool in estimating sea and glacial ice surface characteristics with both scatterometers and radiometers exhibiting high sensitivity to important ice properties. This dissertation presents an array of studies focused on extracting key surface features from multisensor …
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Remote sensing of ice dynamics in the Beaufort Sea
Arctic summer sea ice extent has undergone dramatic declines over the past several decades, particularly in the Beaufort Sea. The comprehension of the sea ice decline requires an understanding of the annual sea ice retreat during the summer melt season. While there are observations of the seasonal …
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Advancing Arctic coastal erosion measurement and monitoring through UAV-SfM, satellite imagery, and object-based image analysis
… air and water temperatures, reductions in Arctic sea ice extent and duration, sea level rise, and increased storm severity and frequency. Erosion of Arctic coasts can lead to rapid land loss threatening habitat, archaeologically significant sites, modern infrastructure, and communities. Rapid …
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Remote Sensing of Ice Dynamics in the Beaufort Sea
Arctic summer sea ice extent has undergone dramatic declines over the past several decades, particularly in the Beaufort Sea. The comprehension of the sea ice decline requires an understanding of the annual sea ice retreat during the summer melt season. While there are observations of the seasonal …
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Development of biomarker-based proxies for paleo sea-ice reconstructions
The analysis of the sea-ice diatom biomarker IP25 (a mono-unsaturated Highly Branched Isoprenoid (HBI) alkene) in Arctic marine sediments has previously been shown to provide a useful qualitative proxy measure for the past spring sea-ice occurrence. In the Southern Ocean the occurrence and variable …
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Risk of Ship Strike and Noise Pollution to Cetaceans in the Bering Strait
As the Arctic sea ice extent decreases due to global climate change, new commercial shipping routes are opening through the Arctic. All of these routes connect the Arctic Ocean to the Pacific Ocean through the Bering Strait, a bottleneck region between Alaska and Russia. This same Strait is …
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The impact of Arctic amplification on the extratropical jets
… gas forcing has warmed the Arctic at twice the rate of lower latitudes, coinciding with a dramatic decline in Arctic sea ice extent. This manifestation of climate change has ignited a lively and ongoing debate regarding if Arctic warming will significantly influence extreme weather in …
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Factors Influencing the Morphology of Sea Ice
Due to the continuous melting of sea ice and rising sea levels, more studies are conducted on sea ice morphology and factors influencing the growth of ice. Sea ice is an integral part of the global climate system. It plays a vital role in the polar ecosystem, providing a habitat for organisms. Sea …
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Understanding the interannual variability of pCO2 in the sea-ice impacted Southern Ocean
Sea-ice is permeable and plays an active role in the marine carbon cycle via biological and physio-chemical processes. The carbon cycle in seasonally sea-ice-covered waters needs to be better understood due to a lack of observational data and the system's complexity. To characterize the interannual …
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A Virtual Ocean framework for environmentally adaptive, embedded acoustic navigation on autonomous underwater vehicles
… poses the additional operational challenge of an ice-covered, GPSdenied environment. This dissertation demonstrates a framework for a physics-based, model-aided, real-time conversion of recorded travel time into range—the first of its kind—which was essential to the successful AUV deployment and …
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A New Method for Melt Detection on Antarctic Ice-Shelves and Scatterometer Calibration Verification
… radar backscatter measurements from the SeaWinds on QuikScat scatterometer and microwave radiometer measurements from the Special Sensor Microwave/Imager (SSM/I) are used to determine periods of surface melt and freeze in the Antarctic ice-shelves. The normalized radar backscatter …
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