TITLE

FEATURES OF THE WEATHER MODIFICATION ASSESSMENT PROJECT IN THE SOUTHWEST REGION OF SAUDI ARABI

AUTHOR(S)

Kucera, Paul A.; Axisa, Duncan; Burger, Roelof P.; Collins, Don R.; Li, Runjun; Chapman, Michael; Posada, Rafael; Krauss, Terry W.; Ghulam, Ayman S.

PUB. DATE

April 2010

SOURCE

Journal of Weather Modification;Apr2010, Vol. 42 Issue 1, p78

SOURCE TYPE

Academic Journal

DOC. TYPE

Article

ABSTRACT

This paper provides an overview of an ongoing rainfall assessment program that has been conducted in the southwest region of Saudi Arabia in the summers of 2008 and 2009 in conjunction with an intensive airborne measurement program. The goal of the study is to examine summertime convection that is observed over the mountainous region (often referred to as the "escarpment") that is adjacent to the Red Sea. The escarpment provides a focus for orographic precipitation as a result of complex interactions with the sea breeze and upper level thermodynamics. The main interest in the study is to examine clouds that are observed on top of the escarpment. Seasonal precipitation results show two distinct peaks in this region: March-April and August. Evaluation of radar observations during these two peaks indicates the area has distinct characteristics in terms of the diurnal cycle and cell structure. Climatological evaluation indicates there are several distinct precipitation zones in the southwest region. We have initially focused our airborne research program on summer clouds observed over the escarpment. This paper presents observations of clouds measured by aircraft during an intensive study carried out in the summer of 2009 in the southwest region of Saudi Arabia. A total of 35 research flights were flown during the intensive field campaign during the period 5 August 2009 to 31 August 2009. These flights were conducted under the direction of a flight scientist that assisted the pilot in flight planning and in performing the necessary profiles to accomplish the measurement objectives. Research aircraft operations focused primarily on conducting measurements in clouds that are targeted for cloud top-seeding. Cloud measurements describing the evolution of droplet coalescence, supercooled liquid water, cloud ice and precipitation hydrometeors are necessary to the understanding of precipitation formation. From this study, we describe the large annual variability in precipitation in the southwest region of Saudi Arabia. Based on our analysis, we have developed a new conceptual model that summarizes the mechanisms for summer precipitation formation in the southwest region. Observations indicate that convective cells tend to be short-lived with complicated microphysics; the presence and concentration of large cloud droplets suggest that GCCN broaden the cloud droplet spectrum; and ice-phase microphysics is important and seems to be efficient. These results have important ramifications for cloud seeding operations.

ACCESSION #

82261174

 

Related Articles

• WYOMING CLOUD SEEDING EXPERIMENT BEGINS.  // Bulletin of the American Meteorological Society;Apr2006, Vol. 87 Issue 4, p409 

  This article discusses the practice of cloud seeding. Many U.S. Western states spend millions of dollars each year seeding clouds to increase snow or rainfall, though no conclusive research has been performed to test whether the practice is effective or not. A Wyoming Weather Modification Pilot...

• KANSAS COUNTIES OPPOSE FOOLING MOTHER NATURE. Freyman, Russ // Governing;Oct1999, Vol. 13 Issue 1, p58 

  Reports on the dispute over cloud seeding in Kansas. Complaint of Rawlins County farmers on the effect of hail-suppression techniques; Results of an advisory vote on the Western Kansas Modification Program; Counties where hail suppression will be suspended.

• Weather Modification—a Scenario for the Future. List, Roland // Bulletin of the American Meteorological Society;Jan2004, Vol. 85 Issue 1, p51 

  The ever-increasing severe economic damage imposed on national and world wide economies by severe weather, the need for sufficient and safe water resources for an increasing world population, and the threat of adverse climate change led to this critical assessment of the state-of-the-art of...

• Weather Modification: Water--Three Cents Per Acre-Foot? Stark, Donald D. // California Law Review;Dec57, Vol. 45 Issue 5, p698 

  Examines the litigating rights and liabilities arising from activities related to weather modification and artificial rainmaking in California. Findings of a study released by the Department of Public Works concerning the benefits of weather modification operations; Conditions necessary to turn...

• CLOUD SEEDING IN CALIFORNIA: AN EVALUATION OF THE RAINSHADOW EFFECT OF WEATHER MODIFICATION PROJECTS.  // California Geographer;1991, Vol. 31, p105 

  The article focuses on a study which determined whether cloud seeding causes the creation of a rainbow effect, which refers to the precipitation deprivation downwind from the target area of the cloud seeding activity, particularly in California. An overview of some research findings is given...

• The Rainmakers. Carson, Gerald // Natural History;Sep85, Vol. 94 Issue 9, p20 

  Discusses the rainmakers of nomadic societies who believed that nature's draughts could be controlled. Societies that depended on agriculture for food; Fear of drought, which has encouraged sorcerers, chiefs, priests and charlatans to act as rainmakers; Theories of rainmaking and how they were...

• A silver lining. Markels, Alex // U.S. News & World Report;12/16/2002, Vol. 133 Issue 23, p57 

  Profiles a cloud seeding program reputed to have brought a great deal of snow to Colorado and other states in the Western U.S. Description of cloud seeding machine design and use; Scientific principles behind the working of cloud seeding within the clouds; Reports of large amounts of snow and...

• Kicking up a storm. Ravilious, Kate // New Scientist;4/16/2005, Vol. 186 Issue 2495, p40 

  The article discusses rain-making. Several countries have extensive private or public cloud seeding programmes, some of which have been operating for over 50 years. Governments and businesses spend millions in the hope of wringing moisture from the clouds. A team from South Africa has completed...

• Impact of Cloud Microphysics on the Development of Trailing Stratiform Precipitation in a Simulated Squall Line: Comparison of One- and Two-Moment Schemes. Morrison, H.; Thompson, G.; Tatarskii, V. // Monthly Weather Review;Mar2009, Vol. 137 Issue 3, p991 

  A new two-moment cloud microphysics scheme predicting the mixing ratios and number concentrations of five species (i.e., cloud droplets, cloud ice, snow, rain, and graupel) has been implemented into the Weather Research and Forecasting model (WRF). This scheme is used to investigate the...

Read the Article