Low-Frequency Variability in the Stratosphere

"We have run a dry, nonlinear, primitive equation spectral model with no externally forced variability and with a realistic time mean state, and we have observed low frequency variability (LFV) in the stratosphere with timescales on the order of hundreds of days. Time lagged correlations have revealed that this variability is linked to LFV in the emission of longwaves from the troposphere. A set of linear model experiments is performed to determine the source of the stratospheric LFV. One set of runs reveal the lowest levels of the model troposphere as the source of most of the relevant forcing. A second set of runs forced with nonlinear terms has shown that the nonlinear interaction among shortwave, high-frequency eddy thermal anomalies in the troposphere has a ""beating"" effect which emits vertically propagating low-frequency longwaves. We also see that the eddies act in such a way as to offset the effects of linear temperature advection, allowing the thermal eddies to persist for long periods."

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Atmospheric Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Werth, David William

Contributors dc:contributor

• Walter Robinson

• Physics, Atmospheric Science

Language dc:language

eng

Identifier

(MiAaPQ)AAI9812806

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/85983