Two Issues Concerning Surface Frontogenesis

Two Issues Concerning Surface Frontogenesis AbstractWith the Weather Research and Forecasting (WRF) model specifically configured to simulate the intensification and evolution of an extratropical baroclinic wave, this study first investigates why cold fronts are characteristically longer, narrower and more intense than warm fronts in the extratropical atmosphere. It is found that the differential thermal advection by the geostrophic and ageostrophic wind components in the two frontal regions results in a greater thermal contrast across the cold front. The length of the cold front is essentially the length scale of the intensifying baroclinic wave (i.e. of the order of radius of deformation). The frontal system as a whole moves eastward under the influence of a steering flow. In addition, the cold front outpaces the warm front eastward, making the western portion of the warm front progressively occluded and the eastern portion of the warm front shorter. The dynamical processes tend to move the cold front eastward, whereas the diabatic heating processes tend to move it westward, contributing to the narrowness of the cold front.This study also investigates whether, how, and why an upper-level front (ULF) would synergistically interact with a surface front (SF). It is found that a favorable circumstance for such interaction to occur in an observed extratropical cyclone and in the WRF model simulation is when the ULF and SF are roughly parallel to one another with the ULF aloft located a few hundred kilometers to the west of the SF. The relative importance of the “forcing” for the ageostrophic circulation associated with the geostrophic circulation, diabatic heating and friction are diagnosed in such interaction. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of the Atmospheric Sciences American Meteorological Society

Two Issues Concerning Surface Frontogenesis

Loading next page...
 
/lp/ams/two-issues-concerning-surface-frontogenesis-JMnde0ZXPF
Publisher
American Meteorological Society
Copyright
Copyright © American Meteorological Society
ISSN
1520-0469
D.O.I.
10.1175/JAS-D-16-0171.1
Publisher site
See Article on Publisher Site

Abstract

AbstractWith the Weather Research and Forecasting (WRF) model specifically configured to simulate the intensification and evolution of an extratropical baroclinic wave, this study first investigates why cold fronts are characteristically longer, narrower and more intense than warm fronts in the extratropical atmosphere. It is found that the differential thermal advection by the geostrophic and ageostrophic wind components in the two frontal regions results in a greater thermal contrast across the cold front. The length of the cold front is essentially the length scale of the intensifying baroclinic wave (i.e. of the order of radius of deformation). The frontal system as a whole moves eastward under the influence of a steering flow. In addition, the cold front outpaces the warm front eastward, making the western portion of the warm front progressively occluded and the eastern portion of the warm front shorter. The dynamical processes tend to move the cold front eastward, whereas the diabatic heating processes tend to move it westward, contributing to the narrowness of the cold front.This study also investigates whether, how, and why an upper-level front (ULF) would synergistically interact with a surface front (SF). It is found that a favorable circumstance for such interaction to occur in an observed extratropical cyclone and in the WRF model simulation is when the ULF and SF are roughly parallel to one another with the ULF aloft located a few hundred kilometers to the west of the SF. The relative importance of the “forcing” for the ageostrophic circulation associated with the geostrophic circulation, diabatic heating and friction are diagnosed in such interaction.

Journal

Journal of the Atmospheric SciencesAmerican Meteorological Society

Published: Jun 26, 2017

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches

$49/month

Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.

$588

$360/year

billed annually
Start Free Trial

14-day Free Trial