Date of Award

Spring 1-1-2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Atmospheric & Oceanic Sciences

First Advisor

John J. Cassano

Second Advisor

Cora Randall

Third Advisor

Mark Serreze

Fourth Advisor

Andrew Monaghan

Fifth Advisor

David Noone

Abstract

Due to the limited observations in the Antarctic and the challenges in validating numerical weather prediction model output, a new method for evaluating the performance of numerical weather prediction models is presented. Typical model evaluation techniques evaluate models using a case study of a specific event or over a large period of time (i.e. days, months, years, etc.). The new evaluation technique uses the method of self-organizing maps to conduct a weather pattern based model evaluation of the Antarctic Mesoscale Prediction System (AMPS). AMPS is used in the subsequent analysis of the low-level winds over the Ross Ice Shelf.

The dynamics of the low-level wind field over the Ross Ice Shelf are investigated using a case study of a high wind event off the coast of the Prince Olav Mountains and a low-level wind climatology over the Ross Ice Shelf. Both of these analyses use automatic weather station observations and output from AMPS.

The region to the northwest of the Prince Olav Mountains contains some of the fastest mean wind speeds over the Ross Ice Shelf. The case study presented in this dissertation diagnoses the atmospheric dynamics associated with the strong winds in this region, concluding the area of maximum wind speed is a barrier wind corner jet.

The low-level wind climatology presented in this dissertation is based on output from the 15 km Weather Research and Forecasting model run within AMPS and is the first Ross Ice Shelf wind climatology presented at this resolution. The wind climatology provides information on the types of winds present over the Ross Ice Shelf and quantifies the frequency and seasonality of these patterns. Subsequently, a climatology of the Ross Ice Shelf airstream identifies the variability in the position and strength of the Ross Ice Shelf airstream and quantifies the frequency and seasonality of these patterns. The atmospheric dynamics associated with the barrier wind component of the Ross Ice Shelf airstream are analyzed.

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