Geographic & Topographic features of the UAE

Transcription

1 Short description of UAE climate NCMS - UAE

2 Geographic & Topographic features of the UAE UAE. UAE is a Gulf country located between latitudes north and longitudes east. east The UAE is located South-east of the Arabian Gulf between Qatar peninsula to the west and the Musandum peninsula to the east except p Fujairah j which is situated on coast of the sea of Oman. The area is one of extremely shallow seas, with large number of offshore islands and coral reefs and often complex pattern of d banks b k,small ll gulfs lf and d coastline li, which hi h have h f d sand profound influence on its climate. UAE has two distinct land elevation Zones. The larger sandy desert zone covers over 90% of the county county ss surface.the mountain zone consist of mountain ranges parallel to the east coast.

3 ¾Winter In winter, the Siberian high pressure intensifies and extends over g the northeast flow, The cold and dryy Pakistan and Iran, inducing northeast locally known as Elnashi, gets the temperatures down. Weather systems are associated with the passage of upper troughs through region cause rain and strong wind. The amount and frequency of rainfall are unreliable and vary greatly from year to year. With approach of un upper trough, freshening south-easterly winds areas sometimes cause sandstorm conditions over inland areas. As the upper trough begins to move away eastwards, as strong low level north westerly flow usually develops, this is known locally as the Shamal from the Arabic word meaning g north)) bringing g g colder air down. The absolute minimum temperatures are lowest in the interior away from the sea and are close to freezing in the winter months. Between the passage of these troughs, the weather is generally fine and sunny with light diurnal land and sea breezes and occasional early morning fog.

4 ¾Autumn This is the most settled and pleasant time of the year with weak pressure gradient over the gulf. Land & sea breezes continue to dominate the local weather. Temperatures also fall markedly during this period Occurrence of fog increase due to the increased overnight cooling. By late of November it is possible for an upper trough to move through the region bringing more extensive cloud and perhaps some rainfall.

5 p g ¾Spring Moving from winter to spring the frequency of westerly disturbances gradually d ll decreases d. Rain and thunderstorms can still occur if an active weather system cross the area, but this more likely over the northern Gulf. Maximum temperatures increase rapidly as the frequency of colder north-westerly shamals reaching the region decreases.

6 ¾Summer Afternoon thunderstorms often develop over the Hajar Mountains to the east of Al Ain and there may be some rainfall over mountains and surrounding plains also can lead to a gust front. Thunderstorms can also develop during the summer months but usually only over the Hajar Mountains.They are a side effect of the Indian monsoon, when unstable bl air i in i the h middle iddl levels l l can be b adverted d d over the h sea off Oman O f from India.The mountains provide an elevated heat source during the daytime and this,combined with local convergence between land and sea breezes, leads to instability. Strong south easterly winds also occur in summer when a deep heat low develops over the Rub Al Khali,lift the sand from the interior and transport it over the coastal strip. The highest temperatures occur in the south - western part of the emirates in summer. The most uncomfortable conditions occur in the late summer along the coastal with humidity above 90 %. Minimum Temperatures start to decrease in September and this leads to an increase in the incidence of early morning fog.

7 Air Temperature c : Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mean Mean Max Mean Min Extreme Max Extreme Min ¾The Extreme maximum air temperature reached 52.1 c in 2002 at Al Jazeera B.G located in far west of the country. ¾The lowest minimum air temperature reached to -2.7 c in Jabel Jais.

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9 y Overview of climate data availability. NCMS has successfully collected checked processed and finally archived the whole climatic data available in UAE using climate database CLDB. Surface, upper air, and marine stations. NCMS issues monthly and annual climate reports for synoptic & AWS stations in UAE.

10 Climatological data are controlled for quality at some reasonable level and archived in such a fashion as to be readily accessible,retrievable.

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12 NCMS STATIONS NETWORK Manned Stations (7 Airports). Automatic Upper weather stations (57 stations). air (RS 92 Radiosonde). Ozone ( 1 Brewer). Marine Radar ( 8 Platforms). (6 Radars ).

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