# Impact of the surface temperature and vertical shear of zonal wind on the dynamics of a simple two-layer model of the atmosphere

**Czasopismo**: Acta Geophysica

**Tytuł artykułu**: Impact of the surface temperature and vertical shear of zonal wind on the dynamics of a simple two-layer model of the atmosphere

**Autorzy**:

Teisseyre, R.

Teisseyre, R.

*Institute of Geophysics, Polish Academy of Sciences ul. Księcia Janusza 64, 01-452 Warszawa, Poland, rt@igf.edu.pl*,

Pilchin, A.N.

Pilchin, A.N.

*Universal Geoscience and Environmental Consulting Company, 205 Hilda Ave., Willowdale, Ontario, M2M 4B1, Canada, apilchin1521@rogers.com*,

Bubnov, V.P.

Bubnov, V.P.

*North-West Ltd., Podolskih kursantov 24D, 117546 Moscow, Russia, pavel_pushkarev@mtu-net.ru*,

Bojdys, G.

Bojdys, G.

*Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland, bojdys@geol.agh.edu.pl*,

Essa, K.S.

Essa, K.S.

*Geophysics Department, Faculty of Science, Cairo University, Giza, Egypt, khalid_sa_essa@yahoo.com*,

Pietsch, K.

Pietsch, K.

*Department of Geophysics, Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland, pietsch@agh.edu.pl*,

Kostecki, A.

Kostecki, A.

*Oil and Gas Institute, ul. Lubicz 25A, 31-503 Kraków, Poland, kostecki@inig.pl*,

Bała, M.

Bała, M.

*Faculty of Geology, Geophysics and Environmental Protection, AGH University of Mining and Metallurgy, Al. Mickiewicza 30, 30-059 Kraków, Poland, bala@geolog.geol.agh.edu.pl*,

Brojewski, R.

Brojewski, R.

*Warsaw University, ICM, ul. Pawińskiego 5a, 02-106 Warszawa, Poland; AVIOMET Ltd., ul. Miła 25/7, 01-033 Warszawa, Poland, r.brojewski@aviomet.pl*,

**Abstrakty**: The paper presents and analyzes, from the point of view of smooth dynamic systems theory, a two-layer baroclinic model of the troposphere in geostrophic approximation. The model describes airflow in β-channel within the tropospheric part of the main Hadley circulation cell. It enables to obtain, after application of the Galerkin method, a fairly simple low-parametric dynamic system describing the phenomena of nonlinear interactions, bifurcations and blocking in the atmosphere. This enables to take into consideration such basic factors influencing the atmospheric dynamics like the heat exchange within the surface, orography, vertical variability of zonal wind and hydrostatic stability. Impact of zonal thermal variability of the surface and vertical shear of zonal wind in the troposphere on the orographic bifurcation was investigated and the oscillation character in the dynamic system after Hopf bifurcation of the second kind was analyzed. Additionally, the model dynamics was investigated in conditions in-cluding momentum forcing in the upper and lower parts of the troposphere and excluding orographic interaction, as well as in the conditions of thermal interaction between the troposphere and the surface for the vertical shear of zonal wind in both tropospheric layers. Impact of the mean zonal wind in the troposphere on the prop-erties of model dynamics was assessed. It was proved that zonally varied surface temperature and layered mean zonal wind in the atmosphere are the parameters that have basic influence on the model dynamics. They cause numerous bifurcations and strongly influence the periods of oscillations of the model variables. They are often Hopf bifurcations of the second kind during which tropospheric states fairly distant from the ones before the bifurcations are generated. This significantly influences the model predictability.

**Słowa kluczowe**: atmospheric models, orographic bifurcation, thermal bifurcation, baroclinic atmosphere, zonal wind,

**Wydawnictwo**: Instytut Geofizyki PAN

**Rocznik**: 2007

**Numer**: Vol. 55, no. 2

**Strony**: 231 – 252

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**DOI**:

**Cytuj**: Teisseyre, R. ,Pilchin, A.N. ,Bubnov, V.P. ,Bojdys, G. ,Essa, K.S. ,Pietsch, K. ,Kostecki, A. ,Bała, M. ,Brojewski, R. , Impact of the surface temperature and vertical shear of zonal wind on the dynamics of a simple two-layer model of the atmosphere. Acta Geophysica Vol. 55, no. 2/2007