E-resources
Open access
-
Al Mandoos Abdulla
07/2012Dissertation
The water resource community in the United Arab Emirates (UAE) has had a growing concern about the sustainability of its fresh groundwater resources over longer than the last two decades. In order to enhance precipitation the concept of cloud-seeding is to seed with appropriate cloud condensation nuclei (CCN) or ice nuclei (IN) to either make precipitation develop or more efficiently. A major effort during realization of this research was the development of an infrastructure: a networks of radars and automatic weather stations, an instrumented aircraft with trace gas, aerosol and cloud microphysical instrumentation to determine the background aerosol characteristics of the region and their influence on cloud and precipitation processes. A significant part was intensive collection of observational data including aircraft, radar, surface measurements and satellite. Measurements of CCN showed that background levels were enhanced due to local pollution sources in the region, which resulted in higher cloud droplet concentrations in clouds, making them more continental in nature. The polluted background particles generally work to suppress precipitation development. When desert dust exists in conjunction with sulfates, the dust particles become coated with sulfate, making them more active as cloud condensation nuclei. When the general weather conditions where not favorable for development of strong convection the convective clouds are developed, mainly inland, along the coast line and some on the western slopes of Oman mountain. The most favorable local conditions for cloud development occur on the sunlight side of Oman mountain. Cb clouds also develop on the front side of the sea-breeze circulation. The sea-breeze circulation was the trigger mechanism for many Cb clouds. The accumulated precipitation of convective clouds are obtained by using two methods of measurements, with rain gauges and by radars. The high discrepancies in the precipitation amount are found because the precipitation data taken from rain gauge network is poorly depicted due to the limited resolution and that the radar measurements highly overestimate the rain gauge data due to evaporation of precipitation from the level of radar measurement to the ground. The results of analysis of precipitation from two methodology of measurement give sufficient confidence to conclude that both, rain gauge and radar data are needed for better reproduction of the areal accumulated convective precipitation over a small area during convective precipitation events. Snadbevanje vodom u Ujedinjenim Arapskim Emiratima postaje vrlo veliki problem duže od dve decenije. Da bi se delimično ublažila nestašica preduzete su mere da se izuči da li postoje prirodni uslovi da se povećavaju padavine zasejavanjem oblaka sa kondenzacionim i ledenim jezgrima. Tokom realizacije ovog istraživanja posebna pažnja je posvećena razvoju infrastrukture, naročito mreže radara, mreže automatskih meteoroloških stanica, opremanju aviona sa instrumentima za merenje gasova, aerosola i mikrofizičkih karakteristika oblaka i padavina. Značajan deo posla je bilo intenzivno prikupljanje podataka dobijenih letilicama, radarima, površinskim merenjima i i satelitima. Merenja kondenzacionih čestica su pokazala da je osnovni nivo sadržaja povećan zbog lokalnih izvora zagañenja u regionu, što je rezultiralo većim koncentracijama oblačnih kapljica, što ih čini više kontinentalninim. Kada postoji pustinjska prašina (koja je neaktivna za kondenzaciju) i sulfati iz izvora zagañenja, tada se čestice peska oblažu sa slojem sulfata, tako da postaju aktivne čestice kondenzacije. Ovo je posebno važno u regionu UAE u kojem postoje oba izvora, koji imaju uticaj na procese stvaranja oblaka i padavina. Kada opšti vremenski uslovi nisu povoljni za razvoj jake konvekcije, konvektivni oblaci se razvijaju uglavnom u unutrašnjosti, duž obale, a neki na zapadnim padinama Omanskih planina. Najpovoljniji uslovi za lokalni razvoj oblaka su na zapadnoj strani Omanskih planina. Cb oblaci se takoñe razvijaju na prednjoj strani fronta cirkulacije more-kopno. Ova cirkulacija je bila okidač za razvoj mnogih Cb oblaka. Ove oluje se premeštaju u unutrašnjost u pravcu u kome se proširuje cirkulacija more-kopno. Akumulirane padavina iz konvektivnih oblaka su dobijene korišćenjem dva metoda merenja, sa kišomerima i radarima. Uočavaju se velike razlike u količini padavina. One nastaju zbog toga što padavine uzete iz mreže kišomernih stanica daju lošu sliku zbog ograničenog broja mernih mesta, i što radarska merenja mnogo precenjuju količine padavina usled isparavanja padavina od nivoa radarskog merenja do tla. Rezultati analize padavina dobijenih sa dve metodologije merenja omogućili su da se zaključi da su obe vrste podataka potrebne za što bolje saznanje o stvarno akumuliranim padavinama na tlu. Ovo je naročito potrebno za različite klimatološke i hidrološke analize i prognoze, kao i za aktivnosti vezane za veštačko povećanje padavina.
Author
![loading ... loading ...](themes/default/img/ajax-loading.gif)
Shelf entry
Permalink
- URL:
Impact factor
Access to the JCR database is permitted only to users from Slovenia. Your current IP address is not on the list of IP addresses with access permission, and authentication with the relevant AAI accout is required.
Year | Impact factor | Edition | Category | Classification | ||||
---|---|---|---|---|---|---|---|---|
JCR | SNIP | JCR | SNIP | JCR | SNIP | JCR | SNIP |
Select the library membership card:
If the library membership card is not in the list,
add a new one.
DRS, in which the journal is indexed
Database name | Field | Year |
---|
Links to authors' personal bibliographies | Links to information on researchers in the SICRIS system |
---|
Source: Personal bibliographies
and: SICRIS
The material is available in full text. If you wish to order the material anyway, click the Continue button.