CLIMATOLOGY OF THE BRUNT-VÄISÄLÄ FREQUENCY OVER MILAN, ITALY
Abstract
In this paper we investigate the spatial and temporal variability of N over the city of Milan, using the historical record of soundings in the period 1991–2007, using 00GMT and 12GMT soundings and performing evaluations at intervals 300–700 m, 800–1800 m, 1500–2500 m, 2500–3500 m, 3000–4000 m, 4000–5000 m and 7000–8000 m.
The values obtained reveal that the Brunt-Vaisala frequency is subject to a moderate change with height over the entire observation period, and once the height is fixed shows only weak seasonal changes. At the height interval 800–1800 m, the maximal values of N are observed between December and January, whereas from April to September smaller values of N represent a flat plateau. These variations generally decrease with increasing height. They are still recognizable in the interval 2500–3500 m, and fully diminish at 7000–8000 m.
The values obtained reveal that the Brunt-Vaisala frequency is subject to a moderate change with height over the entire observation period, and once the height is fixed shows only weak seasonal changes. At the height interval 800–1800 m, the maximal values of N are observed between December and January, whereas from April to September smaller values of N represent a flat plateau. These variations generally decrease with increasing height. They are still recognizable in the interval 2500–3500 m, and fully diminish at 7000–8000 m.
About the Authors
Giovanni GrandoniItaly
Enea, Italian National Agency for New Technologies Energy and the Environment
Maria Cristina Mammarella
Italy
Enea, Italian National Agency for New Technologies Energy and the Environment
Maurizio Favaron
Italy
Servizi Territorio, Milan
References
1. Esau I.N., Zilitinkevich S.S. (2006) Universal dependences between turbulent and mean
2. flow parameters in stably and neutrally stratified planetary boundary layers. Nonlinear
3. Processes in Geophysics, 13, 135–144
4. Holton J.R. (2004) An introduction to Dynamic Meteorology, 4th edition, Elsevier Academic
5. Press, Burlington MA, 535 pp.
6. Hutchinson M.F. (1986) ALGORITHM 642: a fast procedure for calculating minimum cross-validation
7. cubic smoothing splines, ACM Transactions on Mathematical Software, 12, 2, 150–153
8. Jacobson M. (2005) Fundamentals of Atmospheric Modeling, 2nd edition, Cambridge
9. University Press, Cambridge, 813 pp.
10. R Development Core Team (2008) R: A Language and Environment for Statistical
11. Computing, R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0,
12. URL http://www.R-project.org
13. Sozzi R., Georgiadis T., Valentini M. (2002) Introduzione alla Turbolenza Atmosferica,
14. Pitagora Editrice, Bologna, 525 pp.
15. Stull R.B. (1988) An Introduction to Boundary Layer Meteorology, Kluwer Academic
16. Publishers, Dordrecht, 670 pp.
17. Zilitinkevich S.S., Baklanov A. (2002) Calculation of the height of the stable boundary layer
18. in practical applications, Boundary Layer Meteorology, 105, 389–409
19. Zilitinkevich S.S., Esau I.N. (2003) The effect of baroclinicity on the equilibrium depth of
20. neutral and stable planetary boundary layers, Q. J. R. Meteorol. Soc., 129, 3339–3356
21. Zilitinkevich S.S., Esau I.N., Baklanov A. (2007) Further comments on the equilibrium height
22. of neutral and stable planetary boundary layers. Quart. J. Roy. Met. Soc., 133, 265–271.
For citation:
Grandoni G., Mammarella M., Favaron M. CLIMATOLOGY OF THE BRUNT-VÄISÄLÄ FREQUENCY OVER MILAN, ITALY. GEOGRAPHY, ENVIRONMENT, SUSTAINABILITY. 2010;3(1):16-24. https://doi.org/10.24057/2071-9388-2010-3-1-16-24
Views: 227
Email this article 