Synoptic and atmospheric stability classification for the united Arab Emirates
Date
2006-11-16T08:51:29Z
Authors
Mandoos, Abdulla
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Abstract
The United Arab Emirates (UAE) is a country that has developed rapidly over the past
thirty years. Future development is going to be hampered by the enormous shortage of
fresh water in the country. It is critically important that a strategic management plan for
water resource management be developed to avoid a water crisis for the population and
environment. The first step in managing water resources is to understand the sources and
sinks of fresh water.
Clearly, one of the most important sources of water to any environment is precipitation
and the atmospheric processes and characteristics that promote or diminish the likelihood
of rainfall over an area.
The synoptic circulation of a region, as well as the thermodynamic structure of the
atmosphere, are important for both frontal and convectively activated rainfall. In the past
little detailed research has been conducted over the UAE and surrounding regions to
classify and characterise atmospheric processes. This study represents the first attempt to
develop a synoptic circulation climatology for the region. Synoptic circulation patterns
have been classified at both the surface and 500 hPa layer over a period of seven years
(1995-2001). In addition, the UAE is located under the descending limb of the Hadley
circulation. As in other parts of the globe, this has severe implications for the vertical
thermodynamic structure of the atmosphere. Atmospheric stability over the UAE has
been evaluated for the period of seven years. The implications of descending air have
been determined with respect to the thermodynamic structure of the atmosphere as a
function of time and space. Vertical Radiosonde data collected over the same seven year
period at the Abu Dhabi International Airport have been analysed to determine the
frequency of occurrence and nature of absolutely stable layers in the atmosphere.
Six circulation patterns that dominate the flow at both the surface and in the upper
atmosphere at 500 hPa have been identified from the synoptic climatology. The
dominant circulation pattern at the surface and upper atmosphere are the Siberian high
and the Subtropical high, respectively. The Siberian high occurs at the surface
predominantly during the winter season with a maximum frequency of occurrence in
January (48%). The Subtropical high occurs in the upper atmosphere throughout the
year, however, it is dominant during the summer months occurring 80 % of the time in
August.
Absolute stable layers are a permanent feature of the atmosphere over the UAE. A
maximum of six layers have been identified in the atmosphere at a given time. Surface
inversions occur throughout the year. Absolute stable layers have been identified at 850,
700, 600, 500 and 400 hPa. The surface inversions as well as the layers at 850 and 700
hPa have a distinctly seasonal pattern of occurrence. The absolute stable layers at the
remaining pressure layers do not vary significantly with season. The surface and 600 hPa
layers are by far the most dominant in the atmosphere and certainly have the most
important control on vertical movement and accumulation of pollutants in the
atmosphere.
Description
Faculty of Science
0207022d
Keywords
Synoptics, Stability, UAE