[Lcefiec] MAÑANA: COLOQUIO:"Mountain torques and Cold surges "

[coloquios]

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Coloquio del Departamento de Ciencias de la Atmósfera y los Océanos
(DCAO)/
Centro de Investigaciones del Mar y la Atmósfera (CIMA)

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Miércoles 9 de Mayo, 13hs, 2º Piso, DCAO, Aula 8

COLOQUIO
Mountain torques and Cold surges (François Lott and Sylvain Mailler)

Dr. François Lott
Laboratoire de Méréorologie Dynamique, CNRS, France

For the major mountain massives (Himalayas, Rockies, and the Andes) 
there is a strong lead-lag relationship between the two equatorial 
components of the torque the mountains excert on the atmosphere (TM1 and 
TM2).  We show that this statistical relationship is intimately related 
to the  development of the cold-surges.
To corroborate that the peaks of the torques represent well the 
dynamical forcing of the cold surges by the mountain, a theoretical 
dynamical model  is  proposed. This model  calculates the linear f-plane 
atmospheric response to a mountain forcing on the sphere. In this model, 
a positive (resp. negative) peak in TM1 produced by a mountain massif in 
the northern (resp. southern) hemisphere is due to a large scale high 
surface pressure anomaly poleward of the massif.
At a later stage, high pressure and low temperature anomalies develop 
in the lower troposphere east of the mountain, explaining the  signal 
onTM2 and providing the favorable conditions for the cold surges 
development.

Lugar: Aula 8, DCAO, 2º Piso
Pabellón 2,
Ciudad Universitaria.

Los esperamos a todos!

Los interesados en hablar con el Dr. Lott, luego del coloquio, escribir 
a pflombaum at cima.fcen.uba.ar

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Grupo Coloquios
Departamento de Ciencias de la Atmosfera y los Oceanos (FCEN-UBA)
Centro de Investigaciones del Mar y la Atmosfera (CONICET-UBA)
Ciudad Universitaria, 2do piso.
email: coloquios at at.fcen.uba.ar
http://www.at.fcen.uba.ar/charlas_not.php
http://www.cima.fcen.uba.ar/espanol/index.htm
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