Low-Frequency Variability of Polar Atmosphere due to Blocking Formations: A Numerical Experiment of Blocking
Arctic climate in winter depends on occurrence of large-scale atmospheric blocking and amplification of planetary waves. Understanding the development of blocking formations is an important research subject in polar regions as well as in middle latitudes for time scales of a month to a season. In th...
Main Author: | |
---|---|
Other Authors: | |
Format: | Text |
Language: | English |
Published: |
1992
|
Subjects: | |
Online Access: | http://www.dtic.mil/docs/citations/ADP007283 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADP007283 |
id |
ftdtic:ADP007283 |
---|---|
record_format |
openpolar |
spelling |
ftdtic:ADP007283 2023-05-15T15:10:37+02:00 Low-Frequency Variability of Polar Atmosphere due to Blocking Formations: A Numerical Experiment of Blocking Tanaka, H. L. ALASKA UNIV FAIRBANKS GEOPHYSICAL INST 1992-03 text/html http://www.dtic.mil/docs/citations/ADP007283 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADP007283 en eng http://www.dtic.mil/docs/citations/ADP007283 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Meteorology Atmospheric Physics *ATMOSPHERICS *BLOCKING *POLAR REGIONS *SYNOPTIC METEOROLOGY CLIMATE ENVIRONMENTS FREQUENCY HARMONICS INSTABILITY LOW FREQUENCY MODELS SEASONS SIMULATION TRANSITIONS ENVIRONMENTAL IMPACT GREENHOUSE EFFECT *Global climate change Component Reports *Planetary Waves Text 1992 ftdtic 2016-02-19T17:39:19Z Arctic climate in winter depends on occurrence of large-scale atmospheric blocking and amplification of planetary waves. Understanding the development of blocking formations is an important research subject in polar regions as well as in middle latitudes for time scales of a month to a season. In this study, we carried out nonlinear numerical simulations of amplification of low-frequency planetary waves and the concurrent development of blocking. The simulations were conducted using a barotropic spectral model derived from three-dimensional spectral primitive equations with a basis of vertical structure functions and Hough harmonics. The model is truncated to include only barotropic Rossby components of the atmosphere with simple physics including biharmonic diffusion, topographic forcing, baroclinic instability, and zonal surface stress. We find that these four physical processes are sufficient to produce a realistic and persistent dipole blocking with a sharp transition from zonal to meridional flows on a sphere. The simulations confirmed an amplification of the meridional dipole mode due to the up-scale energy cascade from synoptic disturbances under an environment of persistent wavenumber 2. The energy supply from synoptic disturbances contributes to the sharp transition from zonal to meridional flows. This article is from 'Proceedings of the International Conference on the Role of the Polar Regions in Global Change Held in Fairbanks, Alaska on 11-15 June 1990. Volume 1', AD-A253 027, p170-175. Text Arctic Climate change Alaska Defense Technical Information Center: DTIC Technical Reports database Arctic Fairbanks |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Meteorology Atmospheric Physics *ATMOSPHERICS *BLOCKING *POLAR REGIONS *SYNOPTIC METEOROLOGY CLIMATE ENVIRONMENTS FREQUENCY HARMONICS INSTABILITY LOW FREQUENCY MODELS SEASONS SIMULATION TRANSITIONS ENVIRONMENTAL IMPACT GREENHOUSE EFFECT *Global climate change Component Reports *Planetary Waves |
spellingShingle |
Meteorology Atmospheric Physics *ATMOSPHERICS *BLOCKING *POLAR REGIONS *SYNOPTIC METEOROLOGY CLIMATE ENVIRONMENTS FREQUENCY HARMONICS INSTABILITY LOW FREQUENCY MODELS SEASONS SIMULATION TRANSITIONS ENVIRONMENTAL IMPACT GREENHOUSE EFFECT *Global climate change Component Reports *Planetary Waves Tanaka, H. L. Low-Frequency Variability of Polar Atmosphere due to Blocking Formations: A Numerical Experiment of Blocking |
topic_facet |
Meteorology Atmospheric Physics *ATMOSPHERICS *BLOCKING *POLAR REGIONS *SYNOPTIC METEOROLOGY CLIMATE ENVIRONMENTS FREQUENCY HARMONICS INSTABILITY LOW FREQUENCY MODELS SEASONS SIMULATION TRANSITIONS ENVIRONMENTAL IMPACT GREENHOUSE EFFECT *Global climate change Component Reports *Planetary Waves |
description |
Arctic climate in winter depends on occurrence of large-scale atmospheric blocking and amplification of planetary waves. Understanding the development of blocking formations is an important research subject in polar regions as well as in middle latitudes for time scales of a month to a season. In this study, we carried out nonlinear numerical simulations of amplification of low-frequency planetary waves and the concurrent development of blocking. The simulations were conducted using a barotropic spectral model derived from three-dimensional spectral primitive equations with a basis of vertical structure functions and Hough harmonics. The model is truncated to include only barotropic Rossby components of the atmosphere with simple physics including biharmonic diffusion, topographic forcing, baroclinic instability, and zonal surface stress. We find that these four physical processes are sufficient to produce a realistic and persistent dipole blocking with a sharp transition from zonal to meridional flows on a sphere. The simulations confirmed an amplification of the meridional dipole mode due to the up-scale energy cascade from synoptic disturbances under an environment of persistent wavenumber 2. The energy supply from synoptic disturbances contributes to the sharp transition from zonal to meridional flows. This article is from 'Proceedings of the International Conference on the Role of the Polar Regions in Global Change Held in Fairbanks, Alaska on 11-15 June 1990. Volume 1', AD-A253 027, p170-175. |
author2 |
ALASKA UNIV FAIRBANKS GEOPHYSICAL INST |
format |
Text |
author |
Tanaka, H. L. |
author_facet |
Tanaka, H. L. |
author_sort |
Tanaka, H. L. |
title |
Low-Frequency Variability of Polar Atmosphere due to Blocking Formations: A Numerical Experiment of Blocking |
title_short |
Low-Frequency Variability of Polar Atmosphere due to Blocking Formations: A Numerical Experiment of Blocking |
title_full |
Low-Frequency Variability of Polar Atmosphere due to Blocking Formations: A Numerical Experiment of Blocking |
title_fullStr |
Low-Frequency Variability of Polar Atmosphere due to Blocking Formations: A Numerical Experiment of Blocking |
title_full_unstemmed |
Low-Frequency Variability of Polar Atmosphere due to Blocking Formations: A Numerical Experiment of Blocking |
title_sort |
low-frequency variability of polar atmosphere due to blocking formations: a numerical experiment of blocking |
publishDate |
1992 |
url |
http://www.dtic.mil/docs/citations/ADP007283 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADP007283 |
geographic |
Arctic Fairbanks |
geographic_facet |
Arctic Fairbanks |
genre |
Arctic Climate change Alaska |
genre_facet |
Arctic Climate change Alaska |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADP007283 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766341605365645312 |