Cryospheric Teleconnections: The Response of Northern Hemisphere Snow to the Atmospheric and Arctic Sea Ice Variations
Item
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Title
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Cryospheric Teleconnections: The Response of Northern Hemisphere Snow to the Atmospheric and Arctic Sea Ice Variations
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Identifier
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d_2009_2013:2887602f6830:10825
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identifier
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11095
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Creator
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Ghatak, Debjani,
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Contributor
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Allan Frei
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Date
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2011
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Language
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English
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Publisher
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City University of New York.
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Subject
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Environmental science | Climate change | Hydrologic sciences | Atmospheric sciences | Arctic Climate | Atmospheric Circulation | Sea Ice | Snow | Teleconnections
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Abstract
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The primary focus of this dissertation is the land-surface snow cover, which plays a significant role in modulating the earth's surface energy balance. It is an indicator of climatic variations as well as a part of the earth's system of feedback mechanisms that control the climate. The main goal of the thesis is to contribute to our understanding of the factors causing variations in snow. In order to fulfill this goal, specific objectives are formulated with a particular focus on an under-utilized snow pack metric, i.e. the snow depth. These objectives include the spatially robust explanation of climate-driven North American snow depth variability as well as the investigation of any evidence of a climate change signal and/or Arctic sea ice loss signal in the Northern Hemisphere snow cover record.;This thesis identifies major winter climate teleconnection modes i.e. the North Atlantic Oscillation (NAO) and the Pacific-North American pattern (PNA) as the two main drivers of the snow depth variations over North America. Furthermore, the distinct mechanistic pathways linking circulation patterns to snow variations are also determined. These involve regional winter circulation patterns and hydrologic fluxes. Next, analyses of observational datasets show increased snow over Siberia during fall and early winter, which may be related to the loss of summer Arctic sea ice. Historic and future simulations of Community Climate System Model version3 (CCSM3) indicate the emergence of a similar signal during the last half of the 21st century. Finally, a suite of Community Atmosphere Model Version 3 (CAM3) experiments is analyzed, which suggests a key role played by the high-latitude surface forcings due to the SST and sea ice in generating the snow signal over the Eurasian landmasses as emerges in observations.;This thesis contributes to the state of the knowledge of snow -- climate interactions by focusing on the snow depth -- climate interaction. Furthermore, the identification of a snow response to the recent climatic changes including the loss of Arctic sea ice is another original contribution. Thus, this work may enhance the prediction capabilities of the future hydro-climatic changes over the high latitude regions.
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Type
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dissertation
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Source
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2009_2013.csv
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degree
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Ph.D.
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Program
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Earth & Environmental Sciences
