A Diagnostic Study of the Time-Mean Atmosphere Over Northwestern Europe during Winter

A Diagnostic Study of the Time-Mean Atmosphere Over Northwestern Europe during Winter AbstractA diagnostic study has been performed to investigate the prospects for developing a time-averaged statistical-dynamical model for making long-range weather forecasts. Estimates are made of nearly all terms in the equations describing the evolution of the time-mean quantities (ū, v̄, T̄, ) and the horizontal second-order eddy statistics (u2, v2, uv, uT) and vT. These calculations were performed over northwestern Europe, using radiosonde observations of wind, temperature and height for the winter of 197611977. Geostrophic winds were estimated from objective analyses, while vertical velocities were determined with a quasi-geostrophic baroclinic model. For each equation, approximate balances are presented on the basis of these estimates.In the equations for the mean quantities the time derivatives are more than one order of magnitude smaller than the unknown second-order eddy statistics. The same holds for the time derivatives of second-order eddy statistics compared with the unknown third-order and ageostrophic terms in the equations for these eddy fluxes. We therefore conclude that the system of time-averaged equations has no capability of describing the evolution of the atmosphere from one specific mean state to another mean state in the futuresince for this purpose a closure of the system or a parameterization of second- order or third-order terms has to be extremely accurate. Even in the case in which only the stationary waves of the mean flow are treated, a higher order closure scheme does not seem to be feasible, for third-order terms and ageostrophic second-order terms are probably large and very difficult to parameterize. This implies that a preferable approach is to explore in greater depth the possibility of parameterizing the second-order statistics directly. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of the Atmospheric Sciences American Meteorological Society

A Diagnostic Study of the Time-Mean Atmosphere Over Northwestern Europe during Winter

Loading next page...
 
/lp/ams/a-diagnostic-study-of-the-time-mean-atmosphere-over-northwestern-X4pEwjJaq6
Publisher
American Meteorological Society
Copyright
Copyright © American Meteorological Society
ISSN
1520-0469
D.O.I.
10.1175/1520-0469(1979)036<1862:ADSOTT>2.0.CO;2
Publisher site
See Article on Publisher Site

Abstract

AbstractA diagnostic study has been performed to investigate the prospects for developing a time-averaged statistical-dynamical model for making long-range weather forecasts. Estimates are made of nearly all terms in the equations describing the evolution of the time-mean quantities (ū, v̄, T̄, ) and the horizontal second-order eddy statistics (u2, v2, uv, uT) and vT. These calculations were performed over northwestern Europe, using radiosonde observations of wind, temperature and height for the winter of 197611977. Geostrophic winds were estimated from objective analyses, while vertical velocities were determined with a quasi-geostrophic baroclinic model. For each equation, approximate balances are presented on the basis of these estimates.In the equations for the mean quantities the time derivatives are more than one order of magnitude smaller than the unknown second-order eddy statistics. The same holds for the time derivatives of second-order eddy statistics compared with the unknown third-order and ageostrophic terms in the equations for these eddy fluxes. We therefore conclude that the system of time-averaged equations has no capability of describing the evolution of the atmosphere from one specific mean state to another mean state in the futuresince for this purpose a closure of the system or a parameterization of second- order or third-order terms has to be extremely accurate. Even in the case in which only the stationary waves of the mean flow are treated, a higher order closure scheme does not seem to be feasible, for third-order terms and ageostrophic second-order terms are probably large and very difficult to parameterize. This implies that a preferable approach is to explore in greater depth the possibility of parameterizing the second-order statistics directly.

Journal

Journal of the Atmospheric SciencesAmerican Meteorological Society

Published: Oct 19, 1979

There are no references for this article.

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 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

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

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off