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3240363 
Journal Article 
Regional impact of an elevated heat source: The Zagros Plateau of Iran 
Zaitchik, BF; Evans, JP; Smith, RB 
2007 
Yes 
Journal of Climate
ISSN: 0894-8755
EISSN: 1520-0442 
20 
16 
4133-4146 
WOS:000248845700004 
The authors propose that a heat- driven circulation from
the Zagros Plateau has a significant impact on the climate of the Middle East Plain ( MEP),
especially summertime winds, air temperature, and aridity. This proposal is examined in numerical
experiments with a regional climate model. Simulations in which the Zagros Plateau was assigned a
highly reflective, "" snowlike"" albedo neutralized the heat- driven circulation and produced an
extra summertime warming of 1 degrees-2 degrees C in the MEP, measured relative to a control
simulation and to the records of the NCEP - NCAR reanalysis project. This effect was largest in
midsummer, when heating on the plateau was greatest. Additionally, simulations with high albedo
on the Zagros showed reduced subsidence and enhanced precipitation in the MEP. These
sensitivities are interesting because the Zagros Plateau lies downwind of the MEP. Analysis of
model results indicates that the sensitivity of the upwind subsidence region to Zagros albedo can
be understood as a linear atmospheric response to plateau heating, communicated upwind by a
steady heat- driven circulation that influences the thermodynamic balance of the atmosphere. This
regional phenomenon adds to the large- scale subsidence patterns established by the Hadley
circulation and the Asian monsoon. Observed patterns of vertical motion in the Middle East, then,
are a combined product of Zagros- induced subsidence and hemispheric- scale circulations.