Date of Award

12-2025

Document Type

Thesis

Degree Name

Master of Science (MS)

Degree Statement

Master of Science in Atmospheric Sciences

Department

Department of Atmospheric Sciences

Granting Institution

University of Alaska Fairbanks

Committee Chair

Polyakov, Igor

Committee Member

Ballinger, Thomas

Committee Member

Bhatt, Uma

Table of Contents

 Chapter 1: Introduction

Chapter 2: Data and methods

2.1 Mooring observations

2.2 Sea ice concentrations

2.3 Atmospheric data from ERA5 reanalysis

2.4 Arctic extratropical cyclones

2.5 Definitions of seasons

2.6 Defining anomalies

2.7 Defining anomalous events

2.8 Defining daily average cyclone position

Chapter 3: Results

3.1 Correlations between cyclones and air-sea parameters

3.1.1 Cyclones' high correlation counts

3.1.2 Regional dependence of air-ice-ocean coupling driven by cyclones

3.1.3 Strongest variables of cyclone coupling

3.1.4 Cyclones impacting the magnitudes of synoptic-scale anomalies

3.2 Case studies

3.2.1 Cases of air-ice-ocean interactions driven by cyclones in the deep western SAO

3.2.2 Case of air-ice-ocean interactions driven by cyclone in the deep eastern SAO and on shelf

Chapter 4: Discussion. Chapter 5: Conclusion

Abstract

Extratropical cyclones are major drivers of variability in the Arctic, influencing sea ice, upper-ocean conditions, and atmosphere-ocean interactions. Understanding their impacts is critical because they can alter the state of the upper ocean, modulate surface heat fluxes, and affect sea ice dynamics, all of which have implications for the regional climate system and future Arctic environmental change. This study quantifies the effects of cyclones on atmosphere-ice-ocean interactions in the Siberian Arctic Ocean using two years of observational data from seven moorings, complemented by satellite measurements of sea ice and atmospheric reanalysis data. Synoptic-scale anomalies in ocean temperature, salinity, current speed, sea ice concentration, surface air temperature, 10-meter wind speed, and surface heat flux were analyzed to assess changes associated with cyclone events. Results indicate that cyclones strongly amplify air-ice-ocean interactions as indicated by increased correlations between the aforementioned parameters. The magnitude of ocean temperature, salinity, and current speed anomalies in the upper ocean also increased by ~20 percent in the presence of nearby cyclones. Sea ice concentration, surface heat flux, salinity, and near-surface temperature were the most strongly affected parameters. Both the anomaly patterns and the relationships between key parameters were similar across the western, eastern, and shallow-water regions of the Siberian Arctic Ocean. Winter case studies show that cyclones can reduce 0.25x0.25° gridcell sea ice concentration values by 15-30%, triggering extreme anomalies in surface heat flux, ocean temperature, and salinity—demonstrating their impact on ice and upper-ocean conditions even outside of the melt season. These findings demonstrate that cyclones exert substantial influence on synoptic-scale variability and enhance connectivity between the atmosphere, sea ice, and upper ocean. The study offers a framework for understanding cyclone-driven processes in the rapidly changing Arctic and emphasizes the importance of cyclone impacts on sea ice conditions, upper-ocean variability, and regional climate change in the high-latitude environment.

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