Role of Arctic Sea Ice Variability in Climate Models
Thesis (M.S.) University of Alaska Fairbanks, 2011 Arctic sea ice plays an important role in climate by influencing surface heat fluxes and albedo, so must be accurately represented in climate models. This study finds that the fully coupled ice-ocean-atmosphere-land Community Climate System Model (C...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/1879 2023-05-15T13:11:20+02:00 Role of Arctic Sea Ice Variability in Climate Models Dammann, Dyre O. Bhatt, Uma Polyakov, Igor Zhang, Xiang 2011-08 http://hdl.handle.net/11122/1879 en_US eng http://hdl.handle.net/11122/1879 Atmospheric Sciences arctic sea ice Thesis ms 2011 ftunivalaska 2023-02-23T21:35:46Z Thesis (M.S.) University of Alaska Fairbanks, 2011 Arctic sea ice plays an important role in climate by influencing surface heat fluxes and albedo, so must be accurately represented in climate models. This study finds that the fully coupled ice-ocean-atmosphere-land Community Climate System Model (CCSM3.0) underestimates day-to-day ice variability compared to observations and employs the Community Atmosphere Model (CAM3.0) to investigate the atmospheric sensitivity to sea ice variability. Three 100-ensemble experiments are forced with climatological, daily-varying, and smoothly-varying sea ice conditions from an anomalously low ice period (September 2006-February 2007). Daily ice variability has a large local impact on the atmosphere when ice undergoes rapid changes, leading to local cooling and subsequent circulation changes. The most notable example of a large-scale atmospheric response occurs over Northern Europe during fall where daily ice variability forces reductions in the number and strength of cyclones, leading to positive sea level pressure anomalies, surface warming, and reduced cloud cover. Signature Page.i Title Page.ii Abstract.iii Table of Contents.iv List of Figures.vi List of Tables.x List of Appendices.xi 1 Introduction.14 1.1 Introduction – Arctic Sea Ice Evolution.14 1.2 Introduction – Impact of Sea Ice on Atmosphere.17 1.3 Model Versus Observed Arctic Sea Ice.21 1.3.1 Data Properties.21 1.3.2 Mean Ice Conditions.22 1.3.3 Standard Deviation.24 1.3.4 Day-to-day Change of Ice Concentration.27 Model, Data and Methods.30 2.1 Model Description.30 2.2 Observations.31 2.2.1 Data Used as Boundary Conditions in CTRL, DAILY and SMTH Experiments.32 2.3 Methods.41 2.3.1 Number of Ensembles.41 2.3.2 Storm Track Algorithm.42 2.3.3 Bandpassed Filtering.43 2 3 4 5 v Results and Discussion.44 3.1 Fall (September – October) Response.44 3.2 Winter (November – February) Response.55 3.3 Stormtrack Response in the Midlatitudes and the Arctic.59 3.4 Ensemble Analysis.62 Summary and Conclusions.65 References.68 Thesis albedo Arctic Sea ice Alaska University of Alaska: ScholarWorks@UA Arctic Fairbanks |
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Open Polar |
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University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
arctic sea ice |
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arctic sea ice Dammann, Dyre O. Role of Arctic Sea Ice Variability in Climate Models |
topic_facet |
arctic sea ice |
description |
Thesis (M.S.) University of Alaska Fairbanks, 2011 Arctic sea ice plays an important role in climate by influencing surface heat fluxes and albedo, so must be accurately represented in climate models. This study finds that the fully coupled ice-ocean-atmosphere-land Community Climate System Model (CCSM3.0) underestimates day-to-day ice variability compared to observations and employs the Community Atmosphere Model (CAM3.0) to investigate the atmospheric sensitivity to sea ice variability. Three 100-ensemble experiments are forced with climatological, daily-varying, and smoothly-varying sea ice conditions from an anomalously low ice period (September 2006-February 2007). Daily ice variability has a large local impact on the atmosphere when ice undergoes rapid changes, leading to local cooling and subsequent circulation changes. The most notable example of a large-scale atmospheric response occurs over Northern Europe during fall where daily ice variability forces reductions in the number and strength of cyclones, leading to positive sea level pressure anomalies, surface warming, and reduced cloud cover. Signature Page.i Title Page.ii Abstract.iii Table of Contents.iv List of Figures.vi List of Tables.x List of Appendices.xi 1 Introduction.14 1.1 Introduction – Arctic Sea Ice Evolution.14 1.2 Introduction – Impact of Sea Ice on Atmosphere.17 1.3 Model Versus Observed Arctic Sea Ice.21 1.3.1 Data Properties.21 1.3.2 Mean Ice Conditions.22 1.3.3 Standard Deviation.24 1.3.4 Day-to-day Change of Ice Concentration.27 Model, Data and Methods.30 2.1 Model Description.30 2.2 Observations.31 2.2.1 Data Used as Boundary Conditions in CTRL, DAILY and SMTH Experiments.32 2.3 Methods.41 2.3.1 Number of Ensembles.41 2.3.2 Storm Track Algorithm.42 2.3.3 Bandpassed Filtering.43 2 3 4 5 v Results and Discussion.44 3.1 Fall (September – October) Response.44 3.2 Winter (November – February) Response.55 3.3 Stormtrack Response in the Midlatitudes and the Arctic.59 3.4 Ensemble Analysis.62 Summary and Conclusions.65 References.68 |
author2 |
Bhatt, Uma Polyakov, Igor Zhang, Xiang |
format |
Thesis |
author |
Dammann, Dyre O. |
author_facet |
Dammann, Dyre O. |
author_sort |
Dammann, Dyre O. |
title |
Role of Arctic Sea Ice Variability in Climate Models |
title_short |
Role of Arctic Sea Ice Variability in Climate Models |
title_full |
Role of Arctic Sea Ice Variability in Climate Models |
title_fullStr |
Role of Arctic Sea Ice Variability in Climate Models |
title_full_unstemmed |
Role of Arctic Sea Ice Variability in Climate Models |
title_sort |
role of arctic sea ice variability in climate models |
publishDate |
2011 |
url |
http://hdl.handle.net/11122/1879 |
geographic |
Arctic Fairbanks |
geographic_facet |
Arctic Fairbanks |
genre |
albedo Arctic Sea ice Alaska |
genre_facet |
albedo Arctic Sea ice Alaska |
op_relation |
http://hdl.handle.net/11122/1879 Atmospheric Sciences |
_version_ |
1766246925703577600 |